External skin treatment composition

ABSTRACT

An external skin treatment composition containing (I) vitamin A (retinol) and (II) as a stabilizer, a chelating agent/a polysaccharide, an oil, polyethylene (propylene) glycol, a hydroxy carboxylate, a neutral amino acid salt, an oil-soluble antioxidant/EDTA/a benzophenone compound, an oil-soluble antioxidant/an acid/a benzophenone compound, an inclusion compound of cyclodextrin including an antioxidant and/or an ultraviolet absorber, butanediol and/or an oil-soluble antioxidant, a water-soluble benzophenone compound, a basic amino acid and the salt thereof, an acidic amino acid and the salt thereof, a polar oil, a water-swellable clay mineral.

This application is a division of application Ser. No. 08/204,286, filedMar. 10, 1994 now U.S. Pat. No. 5,484,816 which is the national stage ofPCT/JP93/00969 filed Jul. 13, 1993.

TECHNICAL FIELD

The present invention relates to an external skin treatment compositionin which the stability of vitamin A is extremely improved.

BACKGROUND ART

It has been well known that vitamin A is effective for prevention ortreatment of keratodermatitis and, prevention of and recovery fromdermal aging.

Vitamin A, however, is structurally very unstable and can readily causeisomerization, decomposition, polymerization, etc., with light, air,heat, metal ion, etc. Thus, it has been difficult to stably formulatevitamin A into an external skin treatment composition.

SUMMARY OF THE INVENTION

Accordingly, the present invention relates to an external skin treatmentcomposition in which the stability of vitamin A is extremely improved byformulating a stabilizer for improving the stability of vitamin A.

In accordance with the present invention, there is provided an externalskin treatment composition comprising (I) vitamin A and (II) at leastone stabilizer selected from the group consisting of (1) chelatingagents and polysaccharides, (2) oils having an iodine value of 70 ormore, (3) polyethylene glycol and/or polypropylene glycol, (4) hydroxycarboxylates, (5) neutral amino acids, (6) (i) at least one oil-solubleantioxidant selected from the group consisting of butyl hydroxytoluene,butyl hydroxyanisole, α,β,γ,δ-tocopherol, nordihydrogualaretin, propylgallate, fatty acid esters of vitamin C and sorbic acid, (ii) at leastone ethylenediaminetetraacetate and (iii) at least one benzophenonecompound, (7) (i) at least one oil-soluble antioxidant selected from thegroup consisting of butyl hydroxytoluene, butyl hydroxyanisole,α,β,γ,δ-tocopherols, nordihydrogualaretin, propyl gallate and fatty acidesters of vitamin C, (ii) at least one compound selected from the groupconsisting of ascorbic acid, ascorbic acid salt, isoascorbic acid,isoascorbic acid salt, sorbic acid and sorbic acid salt and (iii) atleast one benzophenone compound, (8) inclusion compounds ofcyclodextrins including antioxidants and/or ultraviolet absorbers, (9)at least one kind of butanediol and/or at least one oil-solubleantioxidant, (10) at least one water-soluble benzophenone compound, (11)at least one compound selected from the group consisting of basic aminoacids and the salts thereof, (12) at least one compound selected fromthe group consisting of acidic amino acids and the salts thereof, (13)at least one polar oil selected from the group consisting ofpentaerythritol fatty acid esters and trimethylolpropane fatty acidesters, and (14) at least one water-swellable clay mineral.

BEST MODE FOR CARRYING OUT THE INVENTION

In consideration of the above circumstances, the present inventors haveconducted extensive study and research efforts. As a result, it has beenfound that the stability of vitamin A is extremely improved byformulating the specified stabilizer therein. Thus the present inventionhas been achieved.

The present invention will be described in detail below.

As vitamin A used in the present invention, vitamin A (also calledretinol), all-trans type vitamin A or 13-cis type vitamin A isdesirable. A mixture thereof can also be used.

The amount of vitamin A to be formulated into the external skintreatment composition according to the present invention is notparticularly limited. However, if the effect on the skin as a functionof vitamin A is taking into consideration, the amount is 0.0001% byweight or more, based upon the total weight of the composition. Iffurther effects of vitamin A are required, 0.001% by weight or more ofthe same is preferably used. The upper limit of the formulation amountis preferably 1% by weight in view of the properties as an external skintreatment composition.

According to the first embodiment of the present invention, as astabilizer, the combination of a chelating agent and a polysaccharide isused.

As a chelating agent used in the present invention, mention may be madeof inorganic alkali salts of ethylenediaminetetraacetate such as sodiumsalts and potassium salts thereof, organic alkali salts ofethylenediaminetetraacetate such as ethanolamines salts thereof (mono,di, tri and tetra salts), citric acid and inorganic alkali salts ofcitric acid such as sodium and potassium salts thereof, organic alkalisalts of citric acid such as ethanolamine salts and basic amino acidsalts thereof (mono, di, tri salts); metaphosphoric acid salts,polyphosphoric acid salts, tartaric acid salts.

The amount of a chelating agent to be formulated in accordance with thepresent invention is 0.001% by weight or more and the upper limit of theformulation amount cannot be particularly limited. However, when anextremely large amount of the agent is formulated, although the effectsof the present invention are not impaired, crystals of the agent arepossibly deposited or undesirable phenomena may occur, so that qualitiesas external skin treatment compositions cannot be maintained. Theformulation amount is preferably 1% by weight or less.

As polysaccharides used in the present invention, mention may be made ofcellulose, quinsseed, chondroitin sulfate, starch, galactan, dermatansulfate, glycogen, gum arabic, heparan sulfate, hyaluronic acid, gumtraganth, keratan sulfate, chondroitin, gum xanthane, mucoitin sulfate,guargum, dextran, keratosulfate, locust bean gum, succinoglucan,charonin, and the salts thereof.

The amount of polysaccharides to be formulated into the external skintreatment composition of the present invention is not particularlylimited in view of the effects of the present invention. However, it ispreferably 0.00001 to 5.0% by weight.

In the second embodiment of the present invention, as oils having aniodine value of 70 or more to be formulated as a stabilizer, typically,mention may be made of plant oils belonging to the drying oil group suchas linseed oil, tung oil, soybean oil, sunflower oil, walnut oil, enooil, evening primrose oil, cherrykernel oil and grape seed; plant oilsbelonging to the nondrying oil such as sesame oil, rape seed oil, cottonseed oil, rice bran oil and wheat embryo bud oil; avocado oil; oliveoil; camellia oil; macadamia nut oil; fish oils such as sardine oil,mackerel oil, herring oil, cod-liver oil, oyster oil.

In these oils, iodine values are, for example, 168-190 in linseed oil,114-138 in soybean oil, 122-150 in sunflower oil, 94-107 in rape seedoil, 90-121 in cotton seed oil, 75-90 in olive oil, 73-87 in camelliaoil, 136-195 in sardine oil, 99-119 in herring oil.

Further, among free fatty acids and higher alcohols derived from thesefats and oils, those having an iodine value of 70 or more include, forexample, oleic acid, palmitic acid, linoleic acid, linolenic acid,eleostearic acid, γ-linolenic acid, arachidonic acid, eicosapentaeneacid, oleyl alcohol.

One or more kinds of these oils are formulated into the composition. Theformulation amount thereof for the purpose of exhibiting the effects ofthe present invention is preferably 0.01% by weight or more. Further,even if an excess amount of the same is formulated, the effects of thepresent invention are not impaired. However, if an extremely largeamount of the same is formulated, qualities as external skin treatmentcompositions sometimes can be impaired. Thus caution should be taken notto impair the qualities. The formulation amount is particularlypreferably 0.1 to 60% by weight.

According to the third embodiment of the present invention, as astabilizer, one or two or more kinds of compounds selected frompolyethylene glycol (PEG) and/or polypropylene glycol (PPG) areformulated.

As PEG, PPG to be formulated in accordance with the present invention,PEG200, PEG300, PEG400, PEG1500, PEG4000, PEG6000, PEG20000 as well asPPG400, PPG750, PPG1200, PPG2000, PPG3000 have been typically known.

One or more kinds of these compounds are formulated into thecomposition. The formulation amount thereof for the purpose ofexhibiting the effects of the present invention is preferably 0.1% byweight or more. Further, even if an excess amount of the same isformulated, the effects of the present invention are not impaired.However, if an extremely large amount of the same is formulated,qualities as external skin treatment compositions sometimes can beimpaired. Thus caution should be taken not to impair the qualities ofthe composition. The formulation amount is particularly preferably 1 to80% by weight.

In the fourth embodiment of the present invention, as hydroxycarbonatesincluded in the external skin treatment composition as a stabilizer,mention may be made of inorganic alkali salts such as sodium salts andpotassium salts of citric acid, lactic acid, malic acid and tartaricacid, organic alkali salts such as ethanolamine salts and basic aminoacid salts of citric acid, lactic acid, malic acid and tartaric acid(mono, di and tri salts are typically known).

One or two or more kinds thereof are included in the presentcomposition. The formulation amount thereof for the purpose ofexhibiting the effects of the present invention is preferably 0.001% byweight or more. Further, even if an excess amount of the same isformulated, the effects of the present invention are not impaired.However, if an extremely large amount of the same is formulated,qualities as external skin treatment compositions sometimes can beimpaired. Thus caution should be taken not to impair the qualities ofthe composition. The formulation amount is particularly preferably 0.01to 1% by weight.

In the fifth embodiment of the present invention, as neutral amino acidsincluded in the external skin treatment composition as a stabilizer,mention may be made of glycine, alanine, seline, phenylalanine, prolineand hydroxyproline.

One or two or more kinds thereof are included in the presentcomposition. The formulation amount thereof for the purpose ofexhibiting the effects of the present invention is preferably 0.001% byweight or more. Further, even if an excess amount of the same isformulated, the effects of the present invention are not impaired.However, if an extremely large amount of the same is formulated, theformulation amount exceeds individual solubility to possibly cause theprecipitation of the crystals so that qualities as external skintreatment compositions sometimes can be impaired. Thus caution should betaken not to impair the qualities of the composition. The formulationamount is particularly preferably 0.01 to 10% by weight.

In the sixth embodiment of the present invention, as oil-solubleantioxidants included in the external skin treatment composition as astabilizer, mention may be made of butyl hydroxytoluene (BHT), butylhydroxyanisole (BHA), α,β,γ,δ-tocopherols, nordihydrogualaretin, propylgallate, a fatty acid ester of vitamin C and sorbic acid.

An amount thereof to be formulated in accordance with the presentinvention is prefearbly 0.001% by weight or more, more preferably 0.01%by weight or more. In order to maintain the effects of the invention fora long time, the formulation amount is preferably 0.03% by weight. Theupper limit of the formulation amount depends on the form of theexternal skin treatment composition and the formulation amount can beoptionally selected. Thus, although the upper limit cannot be set, inview of the property of the external skin treatment composition, it ispreferably 10% by weight or less.

As ethylenediaminetetraacetate used in the present invention, mentionmay be made of inorganic alkali salts such as sodium salts and potassiumsalts and organic alkali salts such as ethanolamines salts (mono, di,tri, tetra salts).

The formulation amount thereof is 0.001% by weight or more. The upperlimit of the formulation amount cannot be particularly set. However, ifan extremely large amount of the same is formulated, the effects of thepresent invention are not impaired, but crystals can be precipitated toimpair the qualities of the external skin treatment composition. Thusthe formulation amount is preferably 0.005 to 1% by weight.

As the benzophenone compound used in the present invention, mention maybe made of 2,4-dihydroxybenzophenone (hereinafter referred to asbenzophenone-1), 2,2',4,4,-tetrahydroxybenzophenone (hereinafterreferred to as benzophenone-2), 2-hydroxy-4-methoxybenzophenone(hereinafter referred to as benzophenone-3),2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (hereinafter referred toas benzophenone-4), sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate(hereinafter referred to as benzophenone-5),2,2'-dihydroxy-4,4'-dimethoxybenzophenone (hereinafre referred to asbenzophenone-6), 2-hydroxy-5-chlorobenzophenone (hereinafter referred toas benzophenone-7), 2,2'-dihydroxy-4-methoxybenzophenone (hereinafterreferred to as benzophenone-8), disodium 2,2-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-sulfonate (hereinafterreferred to as benzophenone-9),2-hydroxy-4-methoxy-4'-methylbenzophenone (hereinafter referred to asbenzophenone-10) and 2-hydroxy-4-octyloxybenzophenone (hereinafterreferred to as benzophenone-12).

The formulation amount thereof to the external skin treatmentcomposition of the present invention is 0.001% by weight or more. Theupper limit of the formulation amount cannot be particularly set.However, if an extremely large amount of the same is formulated, theeffects of the present invention are not impaired, but crystals can beprecipitated to impair the qualities of the external skin treatmentcomposition. Thus the formulation amount is preferably 0.01 to 10% byweight.

In the seventh embodiment of the present invention, as a stabilizer, areformulated

(A) at least one oil-soluble antioxidant selected from a groupconsisting of butyl hydroxytoluene (BHT), butyl hydroxyanisole (BHA),α,β,γ,δ-tocopherols, nordihydrogualaretin, propyl gallate and a fattyacid ester of vitamin C,

(B) at least one compound selected from the group consisting of ascorbicacid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts,sorbic acid and sorbic acid salts, and

(C) at least one benzophenone compound.

As oil-soluble antioxidants according to the present invention, mentionmay be made of BHT, BHA, α,β,γ,δ-tocopherols, nordihydrogualaretin,propyl gallate and a fatty acid ester of vitamin C.

An amount thereof to be formulated in accordance with the presentinvention is prefearbly 0.001% by weight or more, more preferably 0.01%by weight or more. In order to maintain the effects of the invention fora long time, the formulation amount is preferably 0.03% by weight. Theupper limit of the formulation depends on the forms of the external skintreatment composition and the formulation can be optionally made. Thus,although the upper limit cannot be set, in view of the property of theexternal skin treatment composition, it is preferably 10% by weight.

As ascorbic acid (another name: vitamin C), isoascorbic acid (anothername: erythorbic acid), sorbic acid and salts thereof, mention may bemade of inorganic alkali salts such as sodium salts and potassium saltsthereof as well as organic alkali salts such as ethanolamines salts andbasic amino acids thereof. Particularly, ascorbic acid, sodiumascorbate, isoascorbic acid (another name: erythorbic acid), sodiumisoascorbate (another name: sodium erythorbate), sorbic acid, sodiumsorbate and potassium sorbate are preferably used.

In a system where each acid and a basic substance are co-utilized, asalt also can be formed.

An amount thereof to be formulated in accordance with the presentinvention is prefearbly 0.001% by weight or more. The upper limit of theformulation amount cannot particularly be set. However, if an extremelylarge amount of the same is formulated, the effects of the presentinvention are not impaired, but crystals can be precipitated to impairthe qualities of the external skin treatment composition. Thus theformulation amount is preferably 10% by weight or less.

As the benzophenone compound used in the present invention, mention maybe made of 2,4-dihydroxybenzophenone (hereinafter referred to asbenzophenone-1), 2,2',4,4'-tetrahydroxybenzophenone (hereinafterreferred to as benzophenone-2), 2-hydroxy-4-methoxybenzophenone(hereinafter referred to as benzophenone-3),2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (hereinafter referred toas benzophenone-4), sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate(hereinafter referred to as benzophenone-5),2,2'-dihydroxy-4,4'-dimethoxybenzophenone (hereinafter referred to asbenzophenone-6), 2-hydroxy-5-chlorobenzophenone (hereinafter referred toas benzophenone-7), 2,2'-dihydroxy-4-methoxybenzophenone (hereinafterreferred to as benzophenone-8), disodium2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-sulfonate (hereinafterreferred to as benzophenone-9),2-hydroxy-4-methoxy-4'-methylbenzophenone (hereinafter referred to asbenzophenone-10) and 2-hydroxy-4-octyloxybenzophenone (hereinafterreferred to as benzophenone-12).

The formulation amount thereof to the external skin treatmentcomposition of the present invention is 0.001% by weight or more. Theupper limit of the formulation amount cannot be particularly set.However, if an extremely large amount of the same is formulated, theeffects of the present invention are not impaired, but crystals can beprecipitated to impair the qualities of the external skin treatmentcomposition. Thus the formulation amount is preferably 10% by weight.

The cyclodextrin (CD) used in the present invention is cyclicoligosaccharides such as CD having the structure of α, β or γ due to thedifference in glucose number (α-CD, β-CD, γ-CD); those to which a loweralkyl group is introduced, i.e., methyl CD (M-CD), ethyl CD (E-CD);hydroxyalkylated compounds, i.e., hydroxymethyl CD (HM-CD), hydroxyethylCD (HE-CD), hydroxypropyl CD (HP-CD), hydroxybutyl CD (HB-CD).

Among these, α-CD and γ-CD have good solubility in water, but if theyare produced according to a starch decomposition method, the yield ofthe product is low and therefore, this method is insufficient in view ofthe cost. β-CD is advantageous from the viewpoint of cost, but thesolubility thereof is somewhat insufficient. In each case, if individualproperties are well known and a compound is utilized on the basis ofthese well-known properties, the effects of the present invention can besufficiently obtained.

In view of the frequent utilization thereof for external skin treatmentcompositions, due to their good solubility and low cost, methylated CDand hydroxylakylated CD are preferable, particularly, methyl-β-CD,hydroxyalkyl-β-CD are the most preferable.

The formulation amount of each CD to the external skin treatmentcomposition of the present invention is 0.01% by weight or more. Theupper limit of the formulation amount cannot be particularly limited bythe effects of the present invention. However, if an extremely largeamount of the same is formulated, the effects of the present inventionare not impaired, but crystals can be precipitated to impair thequalities of the external skin treatment composition. Thus, theformulation amount of α-CD and γ-CD is preferably 10% by weight or less.While, regarding β-CD, 1% by weight or less and regarding loweralkylated CD, hydroxyalkylated CD, the amount is 30% by weight or less.

As oil-soluble antioxidants formulated into the external skin treatmentcomposition according to the present invention, mention may be made ofnordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, afatty acid ester of vitamin C and sorbic acid. Among these, BHT, BHA,α,β,γ,δ-tocopherols are preferably used.

The formulation amount thereof used in the present invention ispreferably 0.001% by weight or more, more preferably 0.01%.by weight ormore. In order to maintain the effects of the invention for a long time,the formulation amount is preferably 0.03% by weight. The upper limit ofthe formulation depends on the form of the external skin treatmentcomposition and the formulation can be optionally made. Thus, althoughthe upper limit cannot be set, in view of the property of the externalskin treatment composition, the antioxidant is preferably formulated inthe amount of 1% by weight.

Examples of the ultraviolet absorber used in the present inventioninclude benzophenone compounds represented by2-hydroxy-4-methoxybenzophenone; cinnamic acid compounds represented byoctylmethoxycinnamate, mono/di(methoxycinnamyl)-mono/dioctylglyceride;salicylic compounds represented by octylsalicylate; benzoic acidcompounds represented by paraaminooctylbenzoate; dibenzoylmethanecompounds represented by 4-t-butyl-4' methoxybenzoylmethane.Benzophenone compounds, cinnamic acid compounds and dibenzoylmethanecompounds are preferably used.

The formulation amount thereof used in the present invention ispreferably 0.001% by weight or more, more preferably 0.01% by weight ormore. In order to maintain the effects of the invention for a long time,the formulation amount is preferably 0.03% by weight. The upper limit ofthe formulation depends on the form of the external skin treatmentcomposition and the formulation can be optionally made. Thus, althoughthe upper limit cannot be set, in view of the property of the externalskin treatment composition, it is preferably 1% by weight.

A method for making antioxidants and ultraviolet absorbers to beincluded in the above-described CDs generally comprises the step ofadding an antioxidant and an ultraviolet absorber to an aqueous solutionof CDs (the concentration is 20 to 60% by weight) in an amount of 0.01to 0.2 part on the basis of the amount of CD, then stirring theresulting mixture (50 to 3000 rpm) at a temperature of 20 to 60° C.,whereby the inclusion compound can be obtained. It takes about 2 to 12hours to obtain the same. The inclusion compound thus obtained is in asolubilized or emulsified state in an aqueous solution and can be usedas it is as an external skin treatment composition. Alternatively, thissolution can be lyophilized or spray-dried to form a powder.

Further, it is also possible to separately formulate CDs, an antioxidantand an ultraviolet absorber into an external skin treatment compositionand to effect the inclusion of these compounds together therein.

In the ninth embodiment of the present invention, as butanediols to beformulated as a stabilizer, mention may be made of 1,2-butanediol,1,3-butanediol, 1,4-butanediol.

One or more kinds thereof are included in accordance with the presentinvention. The formulation amount thereof for the purpose of exhibitingthe effects of the present invention is preferably 0.01% by weight ormore. Further, even if an excess amount of the same is formulated, theeffects of the present invention are not impaired. However, if anextremely large amount of the same is formulated, qualities as externalskin treatment compositions sometimes can be impaired. Thus the cautionshould be taken not to impair the qualities of the composition. Theformulation amount is particularly preferably 0.1 to 40% by weight.

Examples of oil-soluble antioxidants to be formulated in accordance withthe present invention include butyl hydroxytoluene (hereinafter,abbreviated as BHT), butyl hydroxyanisole (hereinafter, abbreviated asBHA), α,β,γ,δ-tocopherols, nordihydrogualaretin, propyl gallate and afatty acid ester of vitamin C.

The formulation amount thereof is preferably 0.001% by weight or more,more preferably 0.005% by weight or more. In order to maintain theeffects of the invention for a long time, the formulation amount ispreferably 0.01% by weight or more. Although the upper limit of theformulation amount cannot be particularly set in view of the effects ofthe present invention, if an extremely large amount of the same isformulated, crystals can be precipitated so that the qualities as theexternal skin treatment composition sometimes can be impaired. Thus,caution should be taken so as not to impair the qualities of thecomposition. A preferable formulation amount is 10% by weight.

In the tenth embodiment of the present invention, as the water-solublebenzophenone compound used as a stabilizer, mention may be made of2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (hereinafter referred toas benzophenone-4) and the salt thereof, sodium2-hydroxy-4-methoxybenzophenone-5-sulfonate (hereinafter referred to asbenzophenone-5) and disodium2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulfonate (hereinafterreferred to as benzophenone-9).

The formulation amount thereof to the external skin treatmentcomposition of the present invention is preferably 0.001% by weight ormore, particularly preferably 0.01% by weight or more. The upper limitof the formulation amount cannot be particularly set. However, if anextremely large amount of the same is formulated, the effects of thepresent invention are not impaired, but crystals can be precipitated toimpair the qualities of the external skin treatment composition. Thusthe formulation amount is preferably 5% by weight or less.

In the eleventh embodiment of the present invention, as a basic aminoacid and the salt thereof to be formulated as a stabilizer, mention maybe made of arginine, lysine, hydroxylysine, ornithine, and thehydrochloride, acetate, aspartate, pyrrolidone carboxylate thereof.

In addition to these, a basic amino acid and other acidic substances areco-utilized in the external skin treatment composition and a salt can beformed in situ.

One or more kinds of these compounds are formulated into thecomposition. The formulation amount thereof for the purpose ofexhibiting the effects of the present invention is required to be 0.001%by weight or more. Further, even if an excess amount of the same isformulated, the effects of the present invention are not impaired.However, if an extremely large amount of the same is formulated,qualities as external skin treatment compositions sometimes can beimpaired, for example, by precipitation of crystals. Thus, cautionshould be taken not to impair the qualities of the composition. Theformulation amount is preferably 0.01 to 5% by weight.

The pH of the system is preferably 6 or more, more preferably 7 or more.

In the twelfth embodiment of the present invention, as an acidic aminoacid and the salt thereof to be formulated as a stabilizer, mention maybe made of acidic amino acids such as aspartic acid and glutamic acid,and inorganic alkali (sodium and potassium) salts thereof as well asorganic alkali (ethanolamine and basic amino acids) salts thereof.Further, pyrrolidone carboxylic acid and the salt thereof also can beapplied.

One or two or more kinds thereof are included in the presentcomposition. The formulation amount thereof for the purpose ofexhibiting the effects of the present invention is preferably 0.001% byweight or more, more preferably 0.01% by weight or more. Further, evenif an excess amount of the same is formulated, the effects of thepresent invention are not impaired. However, if an extremely largeamount of the same is formulated, the formulation amount exceedsindividual solubility to possibly cause the precipitation of crystals sothat qualities as external skin treatment compositions sometimes can beimpaired. Thus, caution should be taken not to impair the qualities ofthe composition. The formulation amount is preferably 10% by weight orless.

In the thirteenth embodiment of the present invention, a polar oil usedas a stabilizer is selected from a group consisting of pentaerythritolfatty acid ester preferably having 6 to 12 carbon atoms andtrimethylolpropane fatty acid ester preferably having 6 to 12 carbonatoms. Examples thereof include pentaerythritol-tetra(2-ethylhexanoate),pentaerythritoltetracaprate, trimethylolpropane-tri(2-ethylhexanoate)and trimethylolpropane-tricaprate.

The amount thereof to be formulated in accordance with the presentinvention cannot be particularly limited because of the wide variety ofutilization forms. However, if an extremely small amount of an oil isused, it cannot solubilize vitamin A or an oil-soluble antioxidant sothat the effects of the present invention cannot be exhibited.Accordingly, an oil is desirably used in an amount over the total amountof vitamin A and an oil-soluble antioxidant to be formulated in theexternal skin treatment composition. The oil is preferably used in anamount of 0.002% by weight or more, more preferably 0.1% by weight ormore. The upper limit of the formulation amount of the oil cannot beparticularly set because of the wide variety of utilization forms.However, the upper limit can be determined by subtracting the sum of anoil-soluble antioxidant and vitamin A from the total amount of theexternal skin treatment composition.

Examples of oil-soluble antioxidants to be formulated into the externalskin treatment composition in accordance with the present inventioninclude BHT, BHA, α,β,γ,δ-tocopherols, nordihydrogualaretin, propylgallate, a fatty acid ester of vitamin C and sorbic acid.

The formulation amount thereof used in the present invention ispreferably 0.001% by weight or more, more preferably 0.01% by weight ormore. In order to maintain the effects of the invention for a long time,the formulation amount is preferably 0.03% by weight.

The upper limit of the formulation depends on the forms of the externalskin treatment composition and the formulation can be optionallydetermined. Thus, although the upper limit cannot be set, in view of theproperty of the external skin treatment composition, it is preferably10% by weight.

In the fourteenth embodiment of the present invention, as awater-swellable clay mineral to be formulated as a stabilizer, mentionmay be made of, generally, a kind of colloidal water-containingaluminumsilicate. Specifical examples thereof include natural orsynthetic smectite such as montmorillonite, bidelite, nontrolite,saponite, hectolite. As the commercially available products, mention maybe made of Kunipia, Smectone (both are available from Kunimine KogyoK.K.), Vegum (available from Vanderbilt K.K.), Laponite (available fromLapolt K.K.), Fluorotetrasilicon modified mica (available from TopeeKogyo K.K.). Further, synthetic mica known as sodium silicic mica andsodium or lithium teniolite also can be used.

The formulation amount thereof in the external skin treatmentcomposition of the present invention is 0.01% by weight or more,preferably 0.1% or more. The upper limit of the formulation amountcannot be particularly set in view of the effects of the presentinvention. However, if an extremely large amount of the same isformulated, gelatin may be produced thus deteriorating the qualities ofthe external skin treatment composition. Thus, caution should be takennot to deteriorate the qualities of the composition. The formulationamount is preferably 50% by weight or less.

Examples of an antioxidant to be formulated in accordance with thepresent invention include butyl hydroxytoluene (hereinafter abbreviatedas BHT), butyl hydroxyanisole (hereinafter abbreviated as BHA),nordihydrogualaretin, α,β,γ,δ-tocopherols, propyl gallate, vitamin C(ascorbic acid), erythorbic acid (isoascorbic acid), erythorbate,vitamin C fatty acid ester, sorbic acid and sorbic acid salt.

The formulation amount thereof used in the present invention ispreferably 0.001% by weight or more, more preferably 0.01% by weight ormore. In order to maintain the effects of the invention for a long time,the formulation amount is preferably 0.03% by weight.

The upper limit of the formulation amount depends on the forms of theexternal skin treatment composition and the formulation can beoptionally determined. Thus, although the upper limit cannot be set, inview of the property of the external skin treatment composition, it ispreferably 10% by weight.

Examples of the ultraviolet absorber used in the present inventioninclude benzophenone compounds represented by2-hydroxy-4-methoxybenzophenone,2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and2,2'-dihydroxy-4,4'-dimethoxybenzophenone; cinnamic acid compoundsrepresented by octylmethoxycinnamate,mono/di(methoxycinnamyl)-mono/dioctylglyceride; salicylic compoundsrepresented by octylsalicylate; benzoic compounds represented byparaaminooctylbenzoate; benzoylmethane compounds represented by4-t-butyl-4'-methoxybenzoylmethane.

One or more kinds thereof are formulated in the present composition. Theformulation amount thereof for the purpose of exhibiting the effects ofthe present invention is preferably 0.001% by weight or more. Further,even if an excess amount of the same is formulated, the effects of thepresent invention are not impaired. However, if an extremely largeamount of the same is formulated, qualities as external skin treatmentcompositions can sometimes be impaired. Thus, caution should be takennot to impair the qualities of the composition. The formulation amountis preferably 10% by weight or less.

As a chelating agent used in the present invention, mention may be madeof inorganic alkali salts such as sodium salts and potassium salts ofethylenediaminetetraacetate, organic alkali salts such as ethanol aminessalts of ethylenediaminetetraacetate (mono, di, tri and tetra salts),citric acid and inorganic alkali salts such as sodium and potassiumsalts of citric acid, organic alkali salts such as ethanol amine saltsand basic amino acid salts of citric acid (mono, di, tri and tetrasalts). Further, metaphosphoric acid salts or polyphosphoric acid saltscan be used.

One or two or more kinds thereof are included in the presentcomposition. The formulation amount thereof for the purpose ofexhibiting the effects of the present invention is required to be 0.001%by weight or more. Further, even if an excess amount of the same isformulated, the effects of the present invention are not impaired.However, if an extremely large amount of the same is formulated,crystals can be precipitated so that the qualities as external skintreatment compositions can sometimes be impaired. Thus, caution shouldbe taken not to impair the qualities of the composition. The formulationamount is preferably 1% by weight or less.

In addition to the above-described essential components, the externalskin treatment composition according to the present invention canoptionally contain a conventional base material of the external skintreatment composition usually used in cosmetics and quasi-drugs andother conventional components such as humectant, surfactant,preservative, water, alcohol, thickener, oil, drug, perfume, colorant,and ultraviolet absorber in an amount which does not deteriorate theeffects of the present invention. The composition can be converted toliquid, gel, paste, cream, powder and solid form.

EXAMPLE

The present invention will be further described in more detail, by, butby no means limited to, the following Examples.

Production method and temperature test method of Examples 1-1, 1-2 andComparative Examples 1-1, 1-2

Each oil component is completely dissolved at 60° C., and then has addedthereto a solution of POE(10) oleyl ether, edetic acid salt, ethanol anddipropylene glycol dissolved in purified water, followed by cooling theresulting solution to 40° C. Thereafter, vitamin A is completelydissolved therein, and the solution is sealed in a brown glass sampletube. The tube is further wrapped with aluminum foil to completely cutlight and is stored in a constant temperature bath at 40° C.

                  TABLE 1-1                                                       ______________________________________                                        Cosmetic oil formulation and vitamin A                                        quantitative determination results (% by weight)                                                              Comp.                                                         Example                                                                              Example  Example                                                       1-1    1-2      1-1                                           ______________________________________                                        Vitamin A         0.01     0.02     0.01                                      Disodium edetate  0.001    0.005    --                                        Hyaluronic acid   0.001    0.001    --                                        Purified water    0.1      0.2      --                                        Glycerol tri 2-ethylhexanoate                                                                   balance  balance  balance                                   triglyceride                                                                  Isopropyl myristate                                                                             10       35       10                                        Squalane          15       15       15                                        Dipropylene glycol                                                                              15       15       15                                        Ethanol           8        8        8                                         POE(10) oleyl ether                                                                             2        2        2                                         Vitamin A quantitative determination value                                    Immediately after preparation (%)                                                               100      100      100                                       After two weeks at 40° C. (%)                                                            93       98       56                                        ______________________________________                                    

In Examples 1-1 and 1-2, the stability of vitamin A is improved ascompared with Comparative Example 1-1. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm using ethanolas a solvent, the quantitative determination was effected.

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

                  TABLE 1-2                                                       ______________________________________                                        Emulsion formulation and vitamin A quantitative                               determination results (% by weight)                                                          Exam- Exam-   Comp.   Comp.                                                   ple   ple     Ex.     Ex.                                                     1-3   1-4     1-3     1-3                                      ______________________________________                                        Vitamin A        0.03    0.001   0.03  0.001                                  Disodium edetate 0.01    --      --    --                                     Trisodium citrate                                                                              0.02    0.02    --    --                                     Cetylisoocatnoate                                                                              10      7       10    7                                      Glycerol 2-ethylhexanoate                                                                      2       4       2     4                                      Squalane         2       2       2     2                                      Cetyl alcohol    2       2       2     2                                      Vaseline         1       1       1                                            Glyceryl monostearate                                                                          1.5     1.5     1.5   1.5                                    POE(60) hardened castor oil                                                                    1.3     1.3     1.3   1.3                                    Carboxyvinyl polymer                                                                           0.2     0.3     0.2   0.3                                    Gum xanthane     0.05    0.1     --    --                                     Caustic potash   0.06    0.08    0.06  0.08                                   Glycerol         10      10      10    10                                     Propylene glycol 3       3       3     3                                      Ethyl paraben    0.2     0.2     0.2   0.2                                    Purified water   To total amount 100                                          Vitamin A quantitative determination value                                    Immediately after preparation (%)                                                              100     100     100   100                                    After one month at 40° C. (%)                                                           95      97      31    38                                     ______________________________________                                    

In Examples 1-3 and 1-4, the stability of vitamin A is improved ascompared with Comparative Example. This is the effect according to thepresent invention.

                  TABLE 1-3                                                       ______________________________________                                        Cosmetic lotion and vitamin A quantitative                                    determination results (% by weight)                                                          Exam- Exam-   Exam-   Comp.                                                   ple   ple     ple     Ex.                                                     1-5   1-6     1-7     1-4                                      ______________________________________                                        Disodium edetate 0.5     --      0.05  --                                     Tetrapotassium edetate                                                                         --      0.3     0.05  --                                     Sodium hyaluronate                                                                             0.1     0.05    --    --                                     Soium chondroitin sulfate                                                                      --      --      0.2   --                                     Ethanol          5.0     5.0     5.0   5.0                                    Methyl paraben   0.1     0.1     0.1   0.1                                    Vitamin A        0.0001  0.0001  0.0001                                                                              0.0001                                 Octadodecanol    0.001   0.001   0.001 0.001                                  POE(60) hardened castor oil                                                                    0.4     0.4     0.4   0.4                                    Lactic acid      0.01    0.01    0.01  0.01                                   Sodium lactate   0.1     0.1     0.1   0.1                                    Glycerol         2.0     2.0     2.0   2.0                                    Purified water   To total amount 100                                          Vitamin A quantitative determination value                                    Immediately after preparation (%)                                                              100     100     100   100                                    After two weeks at 40° C. (%)                                                           95      93      91    49                                     ______________________________________                                    

In Examples 1-5, 1-6, and 1-7, the stability of vitamin A is improved ascompared with Comparative Example. This is the effect according to thepresent invention.

    ______________________________________                                        Example 1-8: Cosmetic lotion                                                                     (% by weight)                                              ______________________________________                                        Oleyl alcohol      0.005                                                      Vitamin A          0.0001                                                     POE(50) oleyl ether                                                                              0.7                                                        Trisodium edetate  1                                                          Lactic acid        0.01                                                       Sodium lactate     0.09                                                       Soium chondroitin sulfate                                                                        0.1                                                        Ethanol            8                                                          Glycerol           2                                                          Methyl paraben     0.2                                                        Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 1-9: Cream                                                                              (% by weight)                                               ______________________________________                                        Squalane          15                                                          Glycerol tri 2-ethylhexanoate                                                                   8                                                           Isopropylmyristate                                                                              7                                                           Vitamin A         0.3                                                         Vaseline          2                                                           Butyl paraben     0.1                                                         Propyl paraben    0.1                                                         Glycerol monooleate                                                                             3                                                           Diglyceroldiisostearate                                                                         2                                                           PEG400 dioleate   1                                                           Glycerol          10                                                          Cellulose powder  1                                                           Dipropylene glycol                                                                              5                                                           Disodium edetate  0.01                                                        Triethanolamine   0.02                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 1-10: Oilessence                                                                         (% by weight)                                              ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                    50                                                         Octyldodecanol     20                                                         Squalane           10                                                         Vitamin A          1                                                          Dibutylphthalate   9                                                          Ethyl alcohol      9.989                                                      Cellulose powder   0.01                                                       Sodium edetate     0.001                                                      ______________________________________                                    

    ______________________________________                                        Example 1-11: Oil gel                                                                           (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   60                                                          POE(20) octyldodecylether                                                                       16                                                          Vitamin A         0.1                                                         Glycerol          16                                                          Sodium hyaluronate                                                                              0.01                                                        Disodium edetate  0.05                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 1-12: Cream                                                                             (% by weight)                                               ______________________________________                                        Cetostearyl alcohol                                                                             3.5                                                         Squalane          30.0                                                        Beeswax           3.0                                                         Reduced lanolin   5.0                                                         Ethyl paraben     0.3                                                         POE(50) oleyl alcohol ether                                                                     2.0                                                         Glycerol monostearate                                                                           2.0                                                         Diethanol amine edetate                                                                         0.01                                                        Perfume           0.03                                                        Vitamin A         0.0001                                                      Dermatan sulfate  0.1                                                         Glycerol          15.0                                                        Purified water    balance                                                     ______________________________________                                    

    ______________________________________                                        Example 1-13: Pack (% by weight)                                              ______________________________________                                        Gum xanthane       1.0                                                        Polyvinyl alcohol  10.0                                                       Propylene glycol   7.0                                                        Ethanol            10.0                                                       Vitamin A          0.01                                                       Monosodium edetate 0.1                                                        Methyl paraben     0.05                                                       POE(60) hydrogenated castor oil                                                                  0.2                                                        Perfume            0.05                                                       Purified water     balance                                                    ______________________________________                                    

    ______________________________________                                        Example 1-14: Compact face powder                                                                  (% by weight)                                            ______________________________________                                        Vitamin A            0.0005                                                   Talc                 85.4                                                     Stearic acid         2.5                                                      Squalane             3.5                                                      Sorbitansesquioleate 1.8                                                      Triethanolamine      1.2                                                      Quinsseed            0.001                                                    Salt of edetic acid  0.001                                                    Pigment              q.s.                                                     Perfume              q.s.                                                     ______________________________________                                    

    ______________________________________                                        Example 1-15: Lipstick                                                                           (% by weight)                                              ______________________________________                                        Vitamin A          0.00001                                                    Microcrystalline wax                                                                             3.0                                                        Bees wax           3.0                                                        Ceresin wax        5.0                                                        Liquid paraffin    19.0                                                       Squalane           20.0                                                       Carnauba wax       3.0                                                        Candellira wax     3.0                                                        Gum arabic         0.01                                                       Monosodium salt of edetic acid                                                                   0.01                                                       Color controlling colorant                                                                       7.0                                                        Dibutylhydroxytoluene                                                                            0.05                                                       Perfume            q.s.                                                       Lanolin            balance                                                    ______________________________________                                    

    ______________________________________                                        Example 1-16: Emulsion                                                                          (% by weight)                                               ______________________________________                                        Vitamin A         1.0                                                         Hyaluronic acid   0.1                                                         Tetraethanol amine edetate                                                                      1.0                                                         Ethanol           2.0                                                         Glycerol          10.0                                                        Propylene glycol  3.0                                                         Carboxyvinyl polymer                                                                            0.3                                                         KOH               0.1                                                         Methyl paraben    0.1                                                         Cetanol           2.5                                                         Vaseline          2.0                                                         Squalane          10.0                                                        Isopropyl myristate                                                                             5.0                                                         Glycerylmonostearate                                                                            2.0                                                         POE(25) Cetyl ether                                                                             2.0                                                         Purified water    balance                                                     ______________________________________                                    

    ______________________________________                                        Example 1-17: Emulsion                                                                            (% by weight)                                             ______________________________________                                        Vitamin A           0.3                                                       Chondroitin sulfate 0.01                                                      Trisodium citrate   0.1                                                       Ethanol             5.0                                                       Glycerol            5.0                                                       Propylene glycol    5.0                                                       Carboxyvinyl polymer                                                                              0.2                                                       KOH                 0.06                                                      Methyl paraben      0.2                                                       POE(60) Hydrogenated castor oil                                                                   1.0                                                       Squalane            3.0                                                       Isopropyl myristate 3.0                                                       Purified water      balance                                                   ______________________________________                                    

The external skin treatment compositions of Examples 1-8 to 1-17 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating one or more chelating agents andpolysaccharides such as hyaluronic acid and chondroitin sulfate, thestability of vitamin A can be extremely improved

Example 2-1 to 2-3 and Comparative Example 2-1 to 2-2

                  TABLE 2-1                                                       ______________________________________                                        Vitamin A stability determination                                             results in various oils (% by weight)                                                                        Comp.  Comp.                                   Example      Example  Example  Example                                                                              Example                                 2-1          2-2      2-3      2-1    2-2                                     ______________________________________                                        Olive oil                                                                             99       --       --     --     --                                    (IV = 75)                                                                     Cotton seed                                                                           --       99       --     --     --                                    oil                                                                           (IV = 95)                                                                     Evening --       --       50     --     --                                    primrose                                                                      Oil                                                                           (IV = 190)                                                                    Squalane                                                                              --       --       49     49     99                                    (IV = 1)                                                                      Palm oil                                                                              --       --       --     50     --                                    (IV = 12)                                                                     Vitamin A                                                                              1        1        1      1      1                                    Quantitative determination value of vitamin A                                 Immediately                                                                           100      100      100    100    100                                   after                                                                         preparation                                                                   (%)                                                                           After ten                                                                              93       98       97     58     39                                   days at                                                                       50° C. (%)                                                             ______________________________________                                    

In Examples 2-1, 2-2 and 2-3, the stability of vitamin A is improved ascompared with Comparative Example. This is the effect according to thepresent invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm using ethanolas a solvent, the quantitative determination was effected.

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 2-4: Cream                                                                             (% by weight)                                                ______________________________________                                        Cetanol          3                                                            Glycerylmonostearate                                                                           2                                                            POE(25) Cetyl ether                                                                            1                                                            Stearic acid     3                                                            Vaseline         3                                                            Olive oil (IV = 80)                                                                            3                                                            Cotton seed oil (IV = 100)                                                                     1                                                            Squalane         5                                                            Vitamin A        0.1                                                          BHT              0.05                                                         Perfume          q.s.                                                         Propylene glycol 3                                                            Potassium hydroxide                                                                            0.2                                                          Purified water   To total amount 100                                          ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 2-5: Lipstick                                                                            (% by weight)                                              ______________________________________                                        Solid paraffin     8                                                          Carnauba wax       4                                                          Candellira wax     4                                                          Microcrystalline wax                                                                             6                                                          Hydrogenated lanolin                                                                             15                                                         Castor oil (IV = 85)                                                                             46.7                                                       Oyster oil (IV = 160)                                                                            5                                                          Evening primrose oil (IV = 190)                                                                  3                                                          Vitamin A          1                                                          BHT                0.3                                                        Mixed colorant (red type)                                                                        7                                                          Perfume            q.s.                                                       ______________________________________                                    

Each of the above-described starting materials is thermally melted at80° C., and thereafter, the molten product is poured into a givencontainer to obtain a lipstick.

    ______________________________________                                        Example 2-6: Cosmetic lotion                                                                     (% by weight)                                              ______________________________________                                        Vitamin A          0.0001                                                     Oleyl alcohol (IV = 80)                                                                          0.01                                                       α-tocopherol 0.005                                                      POE(20) Octyldodecanol                                                                           0.8                                                        Ethanol            8                                                          Propylene glycol   3                                                          Glycerol           1                                                          Methyl paraben     0.15                                                       Lactic acid        0.01                                                       Sodium lactate     0.09                                                       Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 2-7: Eye wrinkle oil                                                                      (% by weight)                                             ______________________________________                                        Macadamia nut oil (IV = 75)                                                                       40                                                        Glycerol tri γ-linolenate (IV = 198)                                                        1                                                         Glycerol tri 2-ethylhexanoate                                                                     25                                                        Sunflower oil (IV = 130)                                                                          20                                                        Squalane            10                                                        PEG600 dioleate     2.8                                                       δ-tocopherol  1                                                         Vitamin A           0.2                                                       ______________________________________                                    

    ______________________________________                                        Example 2-8: Night cream                                                                         (% by weight)                                              ______________________________________                                        Olive oil (IV = 80)                                                                              8                                                          Evening primrose oil (IV = 185)                                                                  2                                                          Squalane           20                                                         PEG400 diisostearate                                                                             1                                                          Diglycerol dioleate                                                                              1                                                          Butyl paraben      0.15                                                       Glycerol monoleate 2                                                          Vitamin A          0.25                                                       Glycerol           10                                                         Magnesium sulfate  0.2                                                        Purified water     To total amount 100                                        ______________________________________                                    

The external skin treatment compositions of Examples 2-4 to 2-8 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating an oil having an iodine value of70 or more, the stability of vitamin A can be extremely improved.

Example 3-1 to 3-3 and Comparative Example 3-1 to 3-2

                  TABLE 3-1                                                       ______________________________________                                        Vitamin A stability determination                                             results in various bases (% by weight)                                                 Exam- Exam-   Exam-   Comp.  Comp.                                            ple   ple     ple     Example                                                                              Example                                          3-1   3-2     3-3     3-1    3-2                                     ______________________________________                                        PEG400     99.9    --      --    --     --                                    PEG1500    --      99.9    --    --     --                                    PPG1200    --      --      50    --     --                                    Propylene glycol                                                                         --      --      49.9  29.9   --                                    Squalane   --      --      --    70     99.9                                  Vitamin A  0.1     0.1     0.1   0.1    0.1                                   Quantitative determination result of vitamin A                                Immediately after                                                                        100     100     100   100    100                                   preparation (%)                                                               After five days                                                                          92      93      90    58     39                                    at 50° C. (%)                                                          ______________________________________                                    

In Examples 3-1, 3-2 and 3-3, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm using ethanolas a solvent, the quantitative determination was effected.

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 3-4: Cream                                                                             (% by weight)                                                ______________________________________                                        A.     Cetanol       3                                                               Glyceryl monostearate                                                                       2                                                               POE(25) Cetyl ether                                                                         1                                                               Stearic acid  3                                                               Vaseline      3                                                               Isopropyl myristate                                                                         5                                                               Squalane      5                                                               Vitamin A     0.1                                                             BHT           0.05                                                            Perfume       q.s.                                                            PEG1500       3                                                               Glycerol      9                                                               Potassium hydroxide                                                                         0.2                                                             Purified water                                                                              To total amount 100                                      ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 3-5: Lipstick                                                                          (% by weight)                                                ______________________________________                                        Solid paraffin   8                                                            Carnauba wax     2                                                            Candellira wax   4                                                            Microcrystalline wax                                                                           6                                                            Hydrogenated lanolin                                                                           15                                                           Isopropyl myristate                                                                            To total amount 100                                          Glyceryl diisostearate                                                                         30                                                           PPG3000          15                                                           Vitamin A        1                                                            BHT              0.3                                                          Mixed colorant (red type)                                                                      7                                                            Perfume          q.s.                                                         ______________________________________                                    

Each of the above-described starting materials is thermally melted at80° C., and thereafter, the molten product is poured into a givencontainer to obtain a lipstick.

    ______________________________________                                        Example 3-6: Cosmetic lotion                                                                     (% by weight)                                              ______________________________________                                        Vitamin A          0.0001                                                     Oleyl alcohol      0.001                                                      α-tocopherol 0.005                                                      POE(20) Octyldodecanol                                                                           0.8                                                        Ethanol            8                                                          PEG300             3                                                          PEG1500            1                                                          Methyl paraben     0.15                                                       Lactic acid        0.03                                                       Sodium lactate     0.07                                                       Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 3-7: Eye wrinkle oil                                                                     (% by weight)                                              ______________________________________                                        Olive oil          40                                                         Glycerol tri 2-ethylhexanoate                                                                    26                                                         Squalane           30                                                         PPG4000            2                                                          PEG20000           0.9                                                        δ-tocopherol 1                                                          Vitamin A          0.1                                                        ______________________________________                                    

    ______________________________________                                        Example 3-8: Beauty paste                                                                      (% by weight)                                                ______________________________________                                        PEG300           30                                                           PEG1500          40                                                           PEG4000          10                                                           Vitamin A        0.3                                                          Isopropyl myristate                                                                            5                                                            POE(25) Cetyl ether                                                                            2                                                            Stearic acid     5                                                            Purified water   To total amount 100                                          ______________________________________                                    

    ______________________________________                                        Example 3-9: Night cream                                                                         (% by weight)                                              ______________________________________                                        Squalane           15                                                         Isopropyl myristate                                                                              5                                                          Silicon dioxide    3                                                          Vaseline           6                                                          Glyceryl monoisostearate                                                                         2                                                          POE(7) Hydrogenated castor oil                                                                   1.5                                                        Propyl paraben     0.2                                                        Vitamin A          0.4                                                        PEG6000            3                                                          PEG400             3                                                          Glycerol           17                                                         Purified water     To total amount 100                                        ______________________________________                                    

The external skin treatment compositions of Examples 3-4 to 3-9 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating polyethylene glycol and/orpropylene glycol, the stability of vitamin A can be extremely improved.

Examples 4-1 to 4-3 and Comparative Example 4-1

                  TABLE 4-1                                                       ______________________________________                                        Vitamin A stability determination                                             results in emulsion (% by weight)                                                                                 Comp.                                                Example                                                                              Example  Example  Example                                              4-1    4-2      4-3      4-1                                       ______________________________________                                        Purified water                                                                             To toal amount 100                                               Glycerol     10       10       10     10                                      Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Caustic potash                                                                             0.03     0.03     0.06   0.06                                    Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       Isopropyl myristate                                                                        4        4        4      4                                       Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60) Hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    Trisodium citrate                                                                          0.08     --       0.04   --                                      Sodium lactate                                                                             --       0.09     0.05   --                                      Vitamin A    0.3      0.3      0.3    0.3                                     Quantitative determination value of vitamin A                                 Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two weeks at                                                                         98       93       95     75                                      40° C. (%)                                                             ______________________________________                                    

In Examples 4-1, 4-2 and 4-3, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm using ethanolas a slovent, the quantitative determination was effected.

In the calculation, at the maximum abosrption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 4-4: Cream                                                                             (% by weight)                                                ______________________________________                                        A.     Cetanol       3                                                               Glycerylmonostearate                                                                        2                                                               POE(25) Cetyl ether                                                                         1                                                               Stearic acid  3                                                               Vaseline      3                                                               Olive Oil     3                                                               Isopropyl palmitate                                                                         1                                                               Squalane      5                                                               Vitamin A     0.1                                                             BHT           0.05                                                            Perfume       q.s.                                                     B.     Propylene glycol                                                                            3                                                               Potassium hydroxide                                                                         0.2                                                             Trisodium citrate                                                                           1                                                               Purified water                                                                              To total amount 100                                      ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 4-5: Beauty essence                                                                      (% by weight)                                              ______________________________________                                        Carboxyvinyl polymer                                                                             0.4                                                        Glycerol           5                                                          Propylene glycol   5                                                          Sodium lactate     0.05                                                       Triethanolamine    3.8                                                        POE(60) Hydrogenated castor oil                                                                  0.5                                                        Vitamin A          0.1                                                        Squalane           1                                                          α-tocopherol 0.05                                                       Methyl paraben     0.2                                                        Ethyl alcohol      6                                                          Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 4-6: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        Glycerol          2                                                           Ethanol           7                                                           POE(50) Oleyl ether                                                                             0.5                                                         Oleyl alcohol     0.002                                                       Vitamin A         0.0001                                                      Trisodium citrate 0.1                                                         Methyl paraben    0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 4-7: Oil gel                                                                            (% by weight)                                               ______________________________________                                        Vitamin A         1                                                           Glycerol tri 2-ethylhexanoate                                                                   40                                                          Olive oil         10                                                          BHT               0.1                                                         BHA               0.05                                                        POE(20) Octyldodecyl ether                                                                      16                                                          Glycerol          15                                                          Disodium citrate  0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 4-8: Night Cream                                                                        (% by weight)                                               ______________________________________                                        Squalane          15                                                          Glycerol tri 2-ethylhexanoate                                                                   5                                                           Vaseline          5                                                           Butyl paraben     0.2                                                         Diglycerol diisostearate                                                                        2                                                           PEG400 Diisostearate                                                                            0.5                                                         Vitamin A         0.1                                                         Glycerol          10                                                          Trisodium citrate 0.3                                                         Sodium lactate    0.1                                                         Lactic acid       0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 4-4 to 4-8 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating hydroxycarboxylate, the stabilityof vitamin A can be extremely improved.

Examples 5-1 to 5-3 and Comparative Example 5-1

                  TABLE 5-1                                                       ______________________________________                                        Vitamin A stability determination                                             results in emulsion (% by weight)                                                                                 Comp.                                                Example                                                                              Example  Example  Example                                              5-1    5-2      5-3      5-1                                       ______________________________________                                        Purified water                                                                             To total amount 100                                              Glycerol     10       10       10     10                                      Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Caustic potash                                                                             0.06     0.06     0.06   0.06                                    Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Cetyl alcohol                                                                              2        2        2      2                                       Butyl alcohol                                                                              1        1        1      1                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       Isopropyl myristate                                                                        4        4        4      4                                       Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60) Hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    BHT          0.03     0.03     0.03   0.03                                    Glycine      1        --       --     --                                      Hydroxy proline                                                                            1        0.5      0.01   --                                      Vitamin A    0.3      0.3      0.3    0.3                                     Quantitative determination result of vitamin A                                Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two weeks at                                                                         98       96       88     55                                      40° C. (%)                                                             ______________________________________                                    

In Examples 5-1, 5-2 and 5-3, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm using ethanolas a solvent, the quantitative determination was effected.

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 5-4: Cream (% by weight)                                              ______________________________________                                        A.       Cetanol       3                                                               Glyceryl monostearate                                                                       2                                                               POE(25) Cetyl ether                                                                         1                                                               Stearic acid  3                                                               Vaseline      3                                                               Olive oil     3                                                               Isopropyl myristate                                                                         1                                                               Squalane      5                                                               Vitamin A     0.1                                                             BHT           0.5                                                             Perfume       q.s.                                                   B.       Propylene glycol                                                                            3                                                               Potassium hydroxide                                                                         0.2                                                             Alanine       5                                                               Hydroxy proline                                                                             5                                                               Purified water                                                                              To total amount 100                                    ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 5-5: Beauty essence                                                                      (% by weight)                                              ______________________________________                                        Carboxyvinyl polymer                                                                             0.4                                                        Glycerol           5                                                          Propylene glycol   5                                                          Alanine            1                                                          Triethanolamine    3.4                                                        POE(60) Hydrogenated castor oil                                                                  0.5                                                        Vitamin A          0.1                                                        Squalane           1                                                          α-tocopherol 1                                                          Methyl paraben     0.2                                                        Ethyl alcohol      6                                                          Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 5-6: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        Glycerol          2                                                           Ethanol           7                                                           POE(50) Oleyl ether                                                                             0.5                                                         Oleyl alcohol     0.002                                                       Vitamin A         0.0001                                                      Serine            0.3                                                         Leucine           0.1                                                         Lactic acid       0.02                                                        Sodium lactate    0.07                                                        Methyl paraben    0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 5-7: Oil gel                                                                            (% by weight)                                               ______________________________________                                        Vitamin A         1                                                           Glycerol tri 2-ethylhexanoate                                                                   40                                                          Olive oil         10                                                          BHT               0.2                                                         BHA               0.05                                                        POE(20) Octyldodecyl ether                                                                      16                                                          Glycerol          15                                                          Glycine           0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 5-8: Night cream                                                                        (% by weight)                                               ______________________________________                                        Liquid paraffin   15                                                          Glycerol tri 2-ethylhexanoate                                                                   7                                                           Vaseline          6                                                           Solid paraffin    2                                                           Diglycerol dioleate                                                                             1.5                                                         Triglycerol diisosearate                                                                        1.5                                                         Vitamin A         0.1                                                         Propyl paraben    0.2                                                         Propylene glycol  4                                                           Glycerol          15                                                          Glycine           1                                                           Hydroxyproline    1                                                           Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 5-4 to 5-8 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating, a neutral amino acid, thestability of vitamin A can be extremely improved.

Example 6-1 to 6-2 and Comparative Example 6-1 to 6-2

                  TABLE 6-1                                                       ______________________________________                                        Cosmetic oil formulation and vitamin A.                                       quantitative determination results (% by weight)                                                         Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              6-1    6-2      6-1      6-2                                       ______________________________________                                        Vitamin A    0.01     0.2      0.01   0.2                                     BHT          0.005    0.03     0.005  0.03                                    d1-α-tocopherol                                                                      --       0.01     --     0.01                                    Benzophenone-3                                                                             0.05     0.1      --     --                                      Octylmethoxycinnamate                                                                      --       --       0.05   0.1                                     Disodium edetate                                                                           0.001    0.005    --     0.005                                   Purified water                                                                             0.1      0.2      --     0.2                                     Glycerol tri 2-                                                                            45       20       45     20                                      ethylhexanoate                                                                Isopropyl myristate                                                                        10       35       10     35                                      Squalane     24.834   24.455   24.935 24.455                                  Dipropylene glycol                                                                         10       10       10     10                                      Ethanol      8        8        8      8                                       POE(10) Oleyl ether                                                                        2        2        2      2                                       Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two months at                                                                        93       98       68     82                                      40° C. (%)                                                             ______________________________________                                    

In Examples 6-1 and 6-2, the stability of vitamin A is improved ascompared with Comparative Example. This is the effect according to thepresent invention.

Production method and temperature test method of Examples 6-1, 6-2 andComparative Examples 6-1, 6-2

BHT, tocopherol, benzophenone and octylmethoxycinnamate are eachcompletely dissolved in oil at 60° C., then to the resulting solution isadded a solution of edetate, ethyl alcohol and dipropylene glycoldissolved in purified water, followed by cooling the resulting solutionto 40° C. Thereafter, vitamin A is completely dissolved therein, and thesolution is sealed in a brown glass sample tube. The tube is furtherwrapped with aluminum foil to completely cut light and is stored in aconstant temperature bath at 40° C.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm using ethanolas a solvent, the quantitative determination was effected.

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

Production method and temperature test method of Examples 6-3. 6-4 andComparative Examples 6-3, 6-4

BHT, tocopherol and benzophenone-2 are each completely dissolved in oiland a surfactant at 70° C., and thereafter, immediately beforeemulsification, vitamin A is completely dissolved therein to form an oilphase.

Glycerol, propylene glycol, carboxyvinyl polymer, caustic potash,trisodium edetate and benzophenone-5 are completely dissolved inpurified water. The oil phase is added to the resulting aqueous phaseheated to 70° C., then the mixture obtained is emulsified by a homomixertype emulsifier. Then the resulting product is subjected to a coolingtreatment by a heat exchanger to 30° C. to form an emulsion.

The emulsion is filled in a glass bottle having a metal coat appliedthereto, tightly sealed and is stored in a constant temperature bath at40° C.

                  TABLE 6-2                                                       ______________________________________                                        Emulsion formulation and vitamin A                                            quantitative determination results (% by weight)                                                         Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              6-3    6-4      6-3      6-4                                       ______________________________________                                        Vitamin A    0.3      0.01     0.3    0.01                                    BHT          0.05     0.01     0.05   0.01                                    di-α-tocopherol                                                                      0.01     0.02     0.01   0.02                                    Trisodium edetate                                                                          0.02     0.02     0.02   --                                      Benzophenone-2                                                                             0.1      0.05     --     0.02                                    Benzophenone-5                                                                             --       0.05     --     --                                      Cetylisooctanoate                                                                          10       7        10     7                                       Isopropyl myristate                                                                        2        4        2      4                                       Squalane     2        2        2      2                                       Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     1        1        1      1                                       Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       1.3      1.3      1.3    1.3                                     castor oil                                                                    Carboxyvinyl polymer                                                                       0.2      0.3      0.2    0.3                                     Caustic potash                                                                             0.06     0.08     0.06   0.08                                    Glycerol     10       10       10     10                                      Propylene glycol                                                                           3        3        3      3                                       Ethyl paraben                                                                              0.2      0.2      0.2    0.2                                     Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month at                                                                         97       99       29     22                                      40° C. (%)                                                             ______________________________________                                    

In Examples 6-3 and 6-4, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm usingethanol, the quantitative determination was effected. A sample wasprepared by removing vitamin A from Examples and Comparative Examples(control) and the absorption at 325 nm was measured, which was used forcorrecting an absorbance as the absorbance of a base material.

(absorbance of a sample of Example and Comparative Example at 325nm)-(an absorbance of a countrol)=the absorbance of vitamin A

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 6-5: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        Oleyl alcohol     0.002                                                       Benzophenone-12   0.001                                                       α-tocopherol                                                                              0.001                                                       Vitamin A         0.0001                                                      POE(50) Oleyl ether                                                                             0.7                                                         Lactic Acid       0.1                                                         Sodium lactate    0.9                                                         Ethanol           8                                                           Glycerol          2                                                           Methyl paraben    0.2                                                         Trisodium edetate 0.01                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 6-6: Oil essence                                                                        (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   30                                                          Octyldodecanol    20                                                          Squalane          12                                                          BHT               1                                                           α-tocopherol                                                                              9                                                           Vitamin A         8                                                           Dipropylene glycol                                                                              12.899                                                      Ethyl alcohol     5                                                           Benzophenone      0.1                                                         Disodium edetate  0.001                                                       ______________________________________                                    

    ______________________________________                                        Example 6-7: Cream                                                                              (% by weight)                                               ______________________________________                                        Squalane          15                                                          Glycerol tri 2-ethylhexanoate                                                                   8                                                           isopropyl myristate                                                                             7                                                           BHT               0.05                                                        BHA               0.01                                                        α-tocopherol                                                                              0.01                                                        Vitamin A         0.3                                                         Vaseline          2                                                           Butyl paraben     0.1                                                         Propyl paraben    0.1                                                         Glycerol monooleate                                                                             3                                                           Diglyceroldiisostearate                                                                         2                                                           PEG400 dioleate   1                                                           Glycerol          10                                                          Dipropylene glycol                                                                              5                                                           Disodium edetate  0.01                                                        Benzophenone-6    0.1                                                         Benzophenone-4    0.03                                                        Triethanolamine   0.04                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 6-8: Oil essence                                                                      (% by weight)                                                 ______________________________________                                        Isopropyl myristate                                                                           10                                                            Octyldodecanol  20                                                            Squalane        30                                                            BHT             1                                                             α-tocopherol                                                                            9                                                             Vitamin A       1                                                             Dibutyl phthalate                                                                             9                                                             Ethyl alcohol   9.999                                                         Benzophenone-12 7                                                             Benzophenone-6  3                                                             Sodium edetate  0.001                                                         ______________________________________                                    

    ______________________________________                                        Example 6-9: Oil gel                                                                            (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   60                                                          POE(20) octyldodecyl ether                                                                      16                                                          Vitamin A         0.1                                                         Benzophenone-12   0.1                                                         Glycerol          16                                                          Benzophenone-5    0.05                                                        Trisodium edetate 0.02                                                        BHA               0.01                                                        BHT               0.01                                                        Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 6-5 to 6-9 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating

(A) one or two or more of oil-soluble antioxidant selected from thegroup consisting of a butyl hydroxytoluene, butyl hydroxyanisole,α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate, a fatty acidester of vitamin C and sorbic acid,

(B) one or two or more of ethylenediaminetetraacetate and

(C) one or two or more of benzophenone compound, the stability ofvitamin A can be extremely improved.

Production method and temperature test method of Examples 7-1, 7-2 andComparative Examples 7-1, 7-2

BHT, tocopherol, benzophenone and octylmethoxycinnamate are eachcompletely dissolved in oil at 60° C., then to the resulting solution,is added a solution of sorbic acid and dipropylene glycol dissolved inethyl alcohol, followed by cooling the resulting solution to 40° C.Thereafter, vitamin A is completely dissolved therein, and the solutionis sealed in a brown glass sample tube. The tube is further wrapped withaluminum foil to completely cut light and is stored in a constanttemperature bath at 40° C.

                  TABLE 7-1                                                       ______________________________________                                        Cosmetic oil formulation and vitamin A                                        quantitative determination results (% by weight)                                                         Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              7-1    7-2      7-1      7-2                                       ______________________________________                                        Vitamin A    0.01     0.2      0.01   0.2                                     BHT          0.005    0.03     0.005  0.03                                    d1-α-tocopherol                                                                      --       0.01     --     0.01                                    Benzophenone-3                                                                             0.05     0.1      --     --                                      Octylmethoxycinnamate                                                                      --       --       0.05   0.1                                     Sorbic acid  0.001    0.005    --     0.005                                   Glycerol tri 2-                                                                            45       20       45     20                                      ethylhexanoate                                                                Isopropyl myristate                                                                        10       35       10     35                                      Squalane     To total amount 100                                              Dipropylene glycol                                                                         10       10       10     10                                      Ethanol      8        8        8      8                                       POE(10) Oleyl ether                                                                        2        2        2      2                                       Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two months at                                                                        95       96       71     69                                      40° C. (%)                                                             ______________________________________                                    

Quantitative determination method of vitamin A

Japanese Pharmacopoepia (11th revision) In accordance with the secondmethod of vitamin A quantitative determinaiton method, the quantitativedeterminaiton was effected by an absorbance determination method usingisopropanol. In examples 7-1 and 7-2, the stability of vitamin A isimproved as compared with the Comparative Example. This is the effectaccording to the present invention.

Production method and temperature test method of Examples 7-3, 7-4 andComparative Examples 7-3, 7-4

BHT, tocopherol and benzophenone-2 are each completely dissolved in oiland a surfactant at 70° C., thereafter, immediately beforeemulsification, vitamin A is completely dissolved therein to form an oilphase.

Glycerol, propylene glycol, carboxyvinyl polymer, caustic potash,ascorbic acid and benzophenone-5 are completely dissolved in purifiedwater. The oil phase is added to the resulting aqueous phase heated to70° C., then the mixture obtained is emulsified by a homomixer typeemulsifier. Then the resulting product is subjected to a coolingtreatment by a heat exchanger to 30° C. to form an emulsion.

The emulsion is filled in a glass bottle having a metal coat appliedthereto, tightly sealed and is stored in a constant temperature bath at40° C.

                  TABLE 7-2                                                       ______________________________________                                        Emulsion formulation and vitamin A                                            quantitative determination results (% by weight)                                                         Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              7-3    7-4      7-3      7-4                                       ______________________________________                                        Vitamin A    0.3      0.01     0.3    0.01                                    BHT          0.05     0.01     0.05   0.01                                    d1-α-tocopherol                                                                      0.01     0.02     0.01   0.02                                    Ascorbic acid                                                                              0.05     0.05     0.05   --                                      Benzophenone-2                                                                             0.1      0.05     --     0.05                                    Benzophenone-5                                                                             --       0.05     --     --                                      Cetyl isooctanoate                                                                         10       7        10     7                                       Squalane     5        5        5      5                                       Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     1        1        1      1                                       Glyceryl-    1.5      1.5      1.5    1.5                                     monostearate                                                                  POE(60)      1.3      1.3      1.3    1.3                                     hydrogenated                                                                  castor oil                                                                    Carboxyvinyl 0.2      0.3      0.2    0.3                                     polymer                                                                       Caustic potash                                                                             0.06     0.08     0.06   0.08                                    Glycerol     10       10       10     10                                      Propylene glycol                                                                           3        3        3      3                                       Ethyl paraben                                                                              0.2      0.2      0.2    0.2                                     Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two weeks                                                                            96       98       47     41                                      at 40° C. (%)                                                          ______________________________________                                    

In Examples 7-3 and 7-4, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm usingethanol, the quantitative determination was effected. A sample wasprepared by removing vitamin A from Examples and Comparative Examples(control) and the absorption at 325 nm was measured, which was used forcorrecting an absorbance as the absorbance of a base material.

(absorbance of a sample of Example and Comparative Example at 325nm)-(absorbance of a control)=the absorbance of vitamin A

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 7-5: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        Oleyl alcohol     0.002                                                       Benzophenone      0.001                                                       α-tocopherol                                                                              0.001                                                       Vitamin A         0.0001                                                      POE(50) Oleyl ether                                                                             0.7                                                         Lactic acid       0.1                                                         Sodium lactate    0.9                                                         Ethanol           8                                                           Glycerol          2                                                           Methyl paraben    0.2                                                         Sodium erythorbate                                                                              0.5                                                         (Sodium isoascorbate)                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 7-6: Oil essence                                                                        (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   10                                                          Octyldodecanol    20                                                          Squalane          39                                                          BHT               1                                                           α-tocopherol                                                                              9                                                           Vitamin A         1                                                           Dipropylene glycol                                                                              12.89                                                       Ethyl alcohol     5                                                           Benzophenone      0.1                                                         Sorbic acid       0.01                                                        ______________________________________                                    

    ______________________________________                                        Example 7-7: Cream                                                                              (% by weight)                                               ______________________________________                                        Squalane          15                                                          Glycerol tri 2-ethylhexanoate                                                                   8                                                           Isopropyl myristate                                                                             7                                                           BHT               0.05                                                        BHA               0.01                                                        α-tocopherol                                                                              0.01                                                        Vitamin A         0.3                                                         Vaseline          2                                                           Butyl paraben     0.1                                                         Propyl paraben    0.1                                                         Glycerol monooleate                                                                             3                                                           Diglyceroldiisostearate                                                                         2                                                           PEG400 dioleate   1                                                           Glycerol          10                                                          Dipropyl glycol   5                                                           Sodium ascorbate  0.01                                                        Benzophenone-8    0.1                                                         Benzophenone-4    0.03                                                        Triethanolamine   0.04                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 7-8: Beauty essence                                                                     (% by weight)                                               ______________________________________                                        Glycerol          30                                                          Propylene glycol  10                                                          Olive oil         2                                                           BHT               0.1                                                         α-tocopherol                                                                              0.1                                                         Vitamin A         0.1                                                         Ethyl alcohol     4                                                           Ascorbic acid     10                                                          Potassium sorbate 0.1                                                         Gumxanthane       0.8                                                         POE(60) hydrogenated caster oil                                                                 0.6                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 7-9: Oil gel                                                                            (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   60                                                          POE(20) octyldodecyl ether                                                                      16                                                          Vitamin A         0.1                                                         Benzophenone-12   0.1                                                         Glycerol          16                                                          Erysorbic acid (Isoascorbic acid)                                                               0.05                                                        Benzophenone-5    0.05                                                        BHA               0.01                                                        BHT               0.01                                                        Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 7-5 to 7-9 wereexcellent in the stability of vitamin A in daily use.

In the external skin treatment composition of the present invention, byformulating

(A) at least one oil-soluble antioxidant selected from the groupconsisting of a butyl hydroxytoluene, butyl hydroxyanisole,α,β,γ,δ-tocopoherol, nordihydrogualaretin, propyl gallate and a fattyacid ester of vitamin C,

(B) at least one compound selected from the group consisting of ascorbicacid, ascorbic acid salt, isoascorbic acid, isoascorbic acid salt,sorbic acid and sorbic acid salt, and

(C) at least one benzophenone compound, the stability of vitamin A canbe extremely improved.

Examples 8-1 to 8-2 and Comparative Examples 8-1 to 8-2

                  TABLE 8-1                                                       ______________________________________                                        Vitamin A stability determination                                             results in emulsion (% by weight)                                                                        Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              8-1    8-2      8-1      8-2                                       ______________________________________                                        Purified water                                                                             To total amount 100                                              Glycerol     10       10       10     10                                      Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Caustic potash                                                                             0.06     0.06     0.06   0.06                                    Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       Isopropyl myristate                                                                        4        4        4      4                                       Glycerylmonostearate                                                                       1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    HP-β-CD 5        5        --     --                                      BHT          0.05     --       0.05   --                                      Octylmethoxycinnamate                                                                      --       0.05     --     0.05                                    Vitamin A    0.3      0.3      0.3    0.3                                     Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two weeks                                                                            98       93       65     55                                      at 40° C. (%)                                                          ______________________________________                                    

As compared with Examples 8-1, 8-2, and the Comparative Examples, thestability of vitamin A is improved. This is the effect according to thepresent invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm usingethanol, the quantitative determination was effected. A sample wasprepared by removing vitamin A from Example 8-2 and Comparative Example8-2 (control) and the absorption at 325 nm was measured, which was usedfor correcting an absorbance as the absorbance of a base material.

(Absorbance of a sample of Example and Comparative Example at 325nm)-(Absorbance of a control)=Absorbance of vitamin A

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

                  TABLE 8-2                                                       ______________________________________                                        Emulsion formulation and vitamin A                                            quantitative determination results (% by weight)                                                         Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              8-3    8-4      8-3      8-4                                       ______________________________________                                        β-M-CD  1        1        --     --                                      α-CD   3        1        --     --                                      γ-CD   2        1        --     --                                      BHT          0.05     0.01     0.05   0.01                                    d1-α-tocopherol                                                                      0.01     0.02     0.01   0.02                                    Vitamin A    0.3      0.01     0.3    0.01                                    Cetyl isooctanoate                                                                         10       7        10     7                                       Squalane     5        2        5      2                                       Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     1        1        1      1                                       Glyceryl-    1.5      1.5      1.5    1.5                                     monostearate                                                                  POE(60)      1.3      1.3      1.3    1.3                                     hydrogenated                                                                  castor oil                                                                    Carboxyvinyl 0.2      0.2      0.2    0.2                                     polymer                                                                       Caustic potash                                                                             0.06     0.06     0.06   0.06                                    Glycerol     10       10       10     10                                      Propylene glycol                                                                           3        3        3      3                                       Methyl paraben                                                                             0.2      0.2      0.2    0.2                                     Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month                                                                            97       94       60     59                                      at 40° C. (%)                                                          ______________________________________                                    

In Examples 8-3 and 8-4, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

    ______________________________________                                        Example 8-5: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        Oleyl alcohol     0.002                                                       β-CD         0.01                                                        BHA               0.001                                                       Vitamin A         0.0001                                                      POE(50) Oleyl ether                                                                             0.7                                                         Lactic acid       0.01                                                        Sodium lactate    0.09                                                        Ethanol           5                                                           Glycerol          1                                                           Methyl paraben    0.2                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 8-6: Beauty essence                                                                     (% by weight)                                               ______________________________________                                        HP-β-CD      30                                                          BHT               1                                                           Vitamin A         1                                                           Isopropyl myristate                                                                             10                                                          POE(60) hydrogenated caster oil                                                                 1                                                           POE(20) sorbitan laurate                                                                        1                                                           Carboxyvinyl polymer                                                                            0.3                                                         Triethanolamine   2.3                                                         Ethanol           3                                                           Methyl paraben    0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 8-7: Cream  (% by weight)                                             ______________________________________                                        HE-β-CD        3                                                         BHT                 0.01                                                      2-hydroxy-4-methoxybenzophenone                                                                   0.02                                                      Vitamin A           0.3                                                       Glycerol tri-2-ethylhexanoate                                                                     10                                                        Vaseline            2                                                         Squalane            18                                                        Butyl paraben       0.1                                                       Propyl paraben      0.1                                                       Glycerol monooleate 3                                                         Diglyceroldiisostearate                                                                           2                                                         PEG400 dioleate     1                                                         Glycerol            10                                                        Dipropylele glycol  5                                                         Purified water      To total amount 100                                       ______________________________________                                    

    ______________________________________                                        Example 8-8: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        Vitamin A         0.001                                                       BHT inclusion-β-HPCD                                                                       5                                                           (BHT:β-HPCD = 1:100)                                                     Glycerol          2                                                           Citric acid       0.03                                                        Trisodium citrate 0.07                                                        Ethanol           5                                                           Methyl paraben    0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 8-9: Beauty powder                                                                         (% by weight)                                            ______________________________________                                        Vitamin A            0.3                                                      α-tocopherolinclusion-α-CD                                                             10                                                       (α-tocopherol:α-CD = 1:150)                                       Ultraviolet absorber inclusion-β-HPCD*                                                        30                                                       (Ultraviolet absorber:β-HPCD = 1:150)                                    D-mannitol           To total amount 100                                      ______________________________________                                         *: Ultraviolet absorber: Octylmethoxycinnamate                           

The external skin treatment compositions of Examples 8-5 to 8-9 wereexcellent in the stability of vitamin A in daily use.

As described hereinabove, in the external skin treatment composition ofthe present invention, by formulating cyclodextrin including anantioxidant and/or an ultraviolet absorber, the stability of vitamin Acan be extremely improved.

Examples 9-1 to 9-2 and Comparative Examples 9-1 to 9-2

                  TABLE 9-1                                                       ______________________________________                                        Vitamin A stability determination                                             results in emulsion (% by weight)                                                                        Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              9-1    9-2      9-1      9-2                                       ______________________________________                                        Purified water                                                                             To total amount 100                                              Glycerol     10       10       10     10                                      Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Caustic potash                                                                             0.06     0.06     0.06   0.06                                    Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       Isopropyl myristate                                                                        4        4        4      4                                       Butylhydroxytoluene                                                                        0.05     0.05     0.05   0.05                                    Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    1,3-butanediol                                                                             0.01     5        --     --                                      Propylene glycol                                                                           --       --       5      --                                      Dipropylene glycol                                                                         --       --       --     5                                       Vitamin A    0.3      0.3      0.3    0.3                                     Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month                                                                            93       92       65     69                                      at 40° C. (%)                                                          ______________________________________                                    

In Examples 9-1 and 9-2, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

    ______________________________________                                        Example 9-3: Cream (% by weight)                                              ______________________________________                                        A.       Cetanol       3                                                               Glycerylmonostearate                                                                        2                                                               POE(25) Cetyl ether                                                                         1                                                               Stearic acid  3                                                               Vaseline      3                                                               Olive oil     3                                                               Isopropyl myristate                                                                         1                                                               Squalane      5                                                               Vitamin A     0.1                                                             BHT           0.05                                                            Perfume       q.s.                                                   B.       1,2-butanediol                                                                              3                                                               1,3-butanediol                                                                              3                                                               1,4-butanediol                                                                              3                                                               Potassium hydroxide                                                                         0.2                                                             Purified water                                                                              To total amount 100                                    ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 9-4: Beauty essence                                                                     (% by weight)                                               ______________________________________                                        Carboxyvinyl polymer                                                                            0.3                                                         1,3-butanediol    25                                                          1,4-butanediol    15                                                          Glycerol          30                                                          Triethanolamine   3.5                                                         POE(60) hydrogenated castor oil                                                                 0.5                                                         Vitamin A         0.1                                                         Squalane          1                                                           α-tocopherol                                                                              0.01                                                        Methyl paraben    0.2                                                         Ethyl alcohol     6                                                           Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 9-5: Cosmetic lotion                                                                    (% by weight)                                               ______________________________________                                        1,3-butanediol    5                                                           Ethanol           7                                                           POE(50) Oleyl ether                                                                             0.5                                                         Oleyl alcohol     0.002                                                       Vitamin A         0.0001                                                      BHT               0.001                                                       Citric acid       0.03                                                        Trisodium citrate 0.07                                                        Methyl paraben    0.1                                                         Disodium edetate  0.03                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 9-6: Oil essence                                                                        (% by weight)                                               ______________________________________                                        Vitamin A         1                                                           Glycerol tri 2-ethylhexanoate                                                                   69                                                          Olive oil         10                                                          BHT               1                                                           α-tocopherol                                                                              9                                                           1,3-butanediol    5                                                           Squalane          5                                                           ______________________________________                                    

    ______________________________________                                        Example 9-7: Night cream                                                                        (% by weight)                                               ______________________________________                                        Vaseline          4                                                           Squalane          15                                                          Liquid paraffin   5                                                           Cetyl octanoate   5                                                           Glycerylmonooleate                                                                              4                                                           POE(5) hydrogenated castor oil                                                                  1                                                           Butyl paraben     0.2                                                         Vitamin A         0.2                                                         1,4-butanediol    2                                                           1,3-butanediol    8                                                           Glycerol          12                                                          Trisodium edetate 0.03                                                        Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 9-3 to 9-7 wereexcellent in the stability of vitamin A in daily use. As describedhereinabove, in the external skin treatment composition of the presentinvention, by formulating butanediol and an oil-soluble antioxidant,stability of vitamin A can be extremely improved.

Examples 10-1, 10-2 and Comparative Examples 10-1, 10-2

Tocopherol, octylmethoxycinnamate, oleyl alcohol, methyl paraben,POE(20) octyldodecyl ether are completely dissolved in ethanol at 40°C., thereafter, vitamin A is completely dissolved therein, and thesolution is quickly cooled to form an alcohol portion. The resultingalcohol portion is added to an aqueous portion wherein other componentsare dissolved in purified water, and sealed in a brown glass sampletube. The tube is further wrapped with aluminum foil to completely cutlight and is stored in a constant temperature bath at 40° C.

                  TABLE 10-1                                                      ______________________________________                                        Vitamin A stability determination                                             results in lotion (% by weight)                                                                          Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              10-1   10-2     10-1     10-2                                      ______________________________________                                        Vitamin A    0.001    0.001    0.001  0.001                                   Oleyl alcohol                                                                              0.005    0.005    0.005  0.005                                   Octylmethoxycinnamate                                                                      --       --       0.001  --                                      Benzophenone-5                                                                             0.001    0.1      --     --                                      Benzophenone-3                                                                             --       --       --     0.01                                    POE(20) Octyldodecyl                                                                       0.8      0.8      0.8    0.8                                     ether                                                                         Ethanol      18       18       18     18                                      Glycerol     3        3        3      3                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Citric acid  0.03     0.03     0.03   0.03                                    Trisodium citrate                                                                          0.07     0.07     0.07   0.07                                    Trisodium edetate                                                                          0.02     0.02     0.02   0.02                                    Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month                                                                            92       95       49     52                                      at 40° C. (%)                                                          ______________________________________                                    

Quantitative determination method of vitamin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

In Examples 10-1 and 10-2, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect produced bythe addition of a water-soluble benzophenone compound according to thepresent invention.

Examples 10-3 to 10-4 and Comparative Examples 10-3 to 10-4

                  TABLE 10-2                                                      ______________________________________                                        Emulsion formulation and vitamin A                                            quantitative determination results (% by weight)                                                         Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              10-3   10-4     10-3     10-3                                      ______________________________________                                        Vitamin A    0.3      0.01     0.3    0.01                                    BHT          0.05     0.01     0.05   0.01                                    d1-α-tocopherol                                                                      0.01     0.02     0.01   0.02                                    Benzophenone-5                                                                             0.1      0.05     --     --                                      Benzophenone-9                                                                             --       0.05     --     --                                      Octylmethoxy-                                                                              --       --       0.1    --                                      cinnamate                                                                     Methoxybenzoyl-                                                                            --       --       --     0.1                                     methane*                                                                      Cetyl        10       7        10     7                                       isooctanoate                                                                  Squalane     5        5        5      5                                       Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     1        1        1      1                                       Glyceryl     1.5      1.5      1.5    1.5                                     monostearate                                                                  POE(60)      1.3      1.3      1.3    1.3                                     hydrogenated                                                                  castor oil                                                                    Carboxyvinyl 0.2      0.3      0.2    0.3                                     polymer                                                                       Caustic potash                                                                             0.06     0.08     0.06   0.08                                    Glycerol     10       10       10     10                                      Propylene glycol                                                                           3        3        3      3                                       Ethyl paraben                                                                              0.2      0.2      0.2    0.2                                     Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month                                                                            97       99       29     22                                      at 40° C. (%)                                                          ______________________________________                                         *4-(1,1-dimethylethyl)-4methoxybenzoylmethane                            

Each oil component containing BHT, and tocopherol, and a surfactant arecompletely dissolved at 70° C., thereafter, immediately beforeemulsification, vitamin A is completely dissolved therein to form an oilphase.

Glycerol, propylene glycol, carboxyvinyl polymer, caustic potash,benzophenone-9 and benzophenone-5 are completely dissolved in purifiedwater. The oil phase is added to the resulting aqueous phase heated to70° C., then the mixture obtained is emulsified by a homomixer typeemulsifier. Then, the resulting product is subjected to a coolingtreatment by a heat exchanger to 30° C. to form an emulsion.

The emulsion is filled in a glass bottle having a metal coat appliedthereto, which is tightly sealed and is stored in a constant temperaturebath at 40° C.

In Examples 10-3 to 10-4, as compared with the Comparative Example, thestability of vitamin A is improved. This is the effect according to thepresent invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm usingethanol, the quantitative determination was effected. A sample wasprepared by removing vitamin A from Example and Comparative Example(control) and the absorption at 325 nm was measured, which was used forcorrecting an absorbance as the absorbance of a base material.

(Absorbance of a sample of Example and Comparative Example at 325nm)-(Absorbance of a control)=Absorbance of vitamin A

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used.

    ______________________________________                                        Example 10-5: Cosmetic lotion                                                                   (% by weight)                                               ______________________________________                                        Oleyl alcohol     0.002                                                       Vitamin A         0.0001                                                      POE(50) Oleyl ether                                                                             0.7                                                         Lactic acid       0.01                                                        Trisodium citrate 0.09                                                        Ethanol           8                                                           Glycerol          2                                                           Methyl paraben    0.2                                                         Benzophenone-12   2.5                                                         Benzophenone-5    2.5                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 10-6: Oil essence                                                                       (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   34                                                          Isopropyl myristate                                                                             35                                                          Dibutyl phthalate 10                                                          Vitamin A         1                                                           Diglyceroldiisostearate                                                                         5                                                           Dipropylene glycol                                                                              14.997                                                      Benzophenone-4    0.001                                                       Trisodium citrate 0.002                                                       ______________________________________                                    

    ______________________________________                                        Example 10-7: Cream                                                                             (% by weight)                                               ______________________________________                                        Squalane          15                                                          Glycerol tri 2-ethylhexanoate                                                                   8                                                           Isopropyl myristate                                                                             7                                                           α-tocopherol                                                                              0.05                                                        Vitamin A         0.3                                                         Vaseline          2                                                           Butyl paraben     0.1                                                         Propyl paraben    0.1                                                         Glycerol monooleate                                                                             3                                                           Diglyceroldiisostearate                                                                         2                                                           PEG400 dioleate   1                                                           Glycerol          10                                                          Dipropylene glycol                                                                              5                                                           Disodium edetate  0.01                                                        Benzophenone-4    0.03                                                        Triethanolamine   0.04                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 10-8: Oil gel                                                                           (% by weight)                                               ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                   60                                                          POE(20) octyldodecyl ether                                                                      16                                                          Vitamin A         0.1                                                         Glycerol          16                                                          Benzophenone-5    0.05                                                        Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 10-5 to 10-8 wereexcellent in the stability of vitamin A in daily use. As describedhereinabove, in the external skin treatment composition of the presentinvention, by formulating a water-soluble benzophenone compound,stability of vitamin A can be extremely improved.

Examples 11-1 to 11-3 and Comparative Example 11-1

                  TABLE 11-1                                                      ______________________________________                                        Vitamin A stability determination                                             results in emulsion (% by weight)                                                                                 Comp.                                                Example                                                                              Example  Example  Example                                              11-1   11-2     11-3     11-1                                      ______________________________________                                        Purified water                                                                             To total amount 100                                              Glycerol     10       10       10     10                                      Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Arginine     0.21     0.28     0.42   0.06                                    Caustic potash                                                                             --       --       --     0.06                                    Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       Isopropyl myristate                                                                        4        4        4      4                                       Glycerylmonostearate                                                                       1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    Butylhydroxytoluene                                                                        0.05     0.05     0.05   0.05                                    Vitamin A    0.3      0.3      0.3    0.3                                     pH (25° C.)                                                                         5.7      6.6      7.4    5.8                                     Vitamin quantitative determination value                                      Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month                                                                            90       92       95     71                                      at 40° C. (%)                                                          ______________________________________                                    

In Examples 11-1, 11-2, and 11-3, the stability of vitamin A is improvedas compared with the Comparative Example. This is the effect accordingto the present invention.

Quantitative determination method of vitamin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

    ______________________________________                                        Example 11-4: Cream                                                                             (% by weight)                                               ______________________________________                                        A.       Cetanol       3                                                               Glycerylmonostearate                                                                        2                                                               POE(25) Cetyl ether                                                                         2                                                               Stearic acid  3                                                               Vaseline      2                                                               Olive oil     3                                                               Isopropyl myristate                                                                         3                                                               Squalane      5                                                               Vitamin A     0.1                                                             BHT           0.05                                                            Perfume       q.s.                                                   B.       Propylene glycol                                                                            3                                                               Potassium hydroxide                                                                         0.27                                                            Arginine      0.001                                                           Purified water                                                                              To total amount 100                                    ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream. (pH=7.3)

    ______________________________________                                        Example 11-5: Beauty essence                                                                    (% by weight)                                               ______________________________________                                        Carboxyvinyl polymer                                                                            0.4                                                         Glycerol          5                                                           Propyl glycol     5                                                           Lysine            0.5                                                         Arginine          4.8                                                         POE(60) hydrogenated castor oil                                                                 0.5                                                         Vitamin A         0.1                                                         Squalane          1                                                           α-tocopherol                                                                              0.05                                                        Methyl paraben    0.2                                                         Ethyl alcohol     6                                                           Purified water    To total amount 100                                                           pH = 6.7                                                    ______________________________________                                    

    ______________________________________                                        Example 11-6: Cosmetic lotion                                                                   (% by weight)                                               ______________________________________                                        Glycerol          2                                                           Ethanol           7                                                           POE(50) Oleyl ether                                                                             0.5                                                         Oleyl alcohol     0.002                                                       Vitamin A         0.0001                                                      Lactic acid       0.03                                                        Arginine          0.1                                                         Ornithine hydrochloride                                                                         1                                                           Methyl paraben    0.1                                                         Purified water    To total amount 100                                                           pH = 6.2                                                    ______________________________________                                    

    ______________________________________                                        Example 11-7: Oil gel                                                                           (% by weight)                                               ______________________________________                                        Vitamin A         0.5                                                         Glycerol tri 2-ethylhexanoate                                                                   40                                                          Olive oil         10                                                          BHT               0.1                                                         BHA               0.05                                                        PHE(20) octyldodecyl ether                                                                      16                                                          Glycerol          15                                                          Lysine hydrochloride                                                                            0.1                                                         Purified water    To total amount 100                                                           pH = 5.5                                                    ______________________________________                                    

    ______________________________________                                        Example 11-8: Night cream                                                                       (% by weight)                                               ______________________________________                                        Solid paraffin    1                                                           Microcrystalline wax                                                                            2                                                           Beeswax           1                                                           Squalane          15                                                          Glycerol tri 2-ethylhexanoate                                                                   10                                                          Diglycerol diisostearate                                                                        3                                                           PEG400 diisostearate                                                                            1                                                           Propyl paraben    0.2                                                         Vitamin A         0.3                                                         Glycerol          10                                                          Propylene glycol  4                                                           Arginine          0.2                                                         Pyrrolidone carboxylic acid                                                                     0.2                                                         Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 11-4 to 11-8 wereexcellent in the stability of vitamin A in daily use.

In the external skin treatment composition of the present invention, byformulating a basic amino acid and/or the salt thereof, stability ofvitamin A can be extremely improved.

Examples 12-1 to 12-3 and Comparative Example 12-1

                  TABLE 12-1                                                      ______________________________________                                        Vitamin A stability determination                                             results in emulsion (% by weight)                                                                                 Comp.                                                Example                                                                              Example  Example  Example                                              12-1   12-2     12-3     12-1                                      ______________________________________                                        Purified water                                                                             To total amount 100                                              Glycerol     10       10       10     10                                      Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Caustic potash                                                                             0.06     0.06     0.06   0.06                                    Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Cetyl alcohol                                                                              2        2        2      2                                       Butyl alcohol                                                                              1        1        1      1                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       Isopropyl myristate                                                                        4        4        4      4                                       Glycerylmonostearate                                                                       1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    BHT          0.03     0.03     0.03   0.03                                    Trisodium edetate                                                                          0.02     0.02     0.02   0.02                                    Arginine aspartate                                                                         0.03     0.03     --     --                                      Monosodium glutamate                                                                       --       0.5      0.01   --                                      Vitamin A    0.3      0.3      0.3    0.3                                     Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two months                                                                           90       96       90     69                                      at 40° C. (%)                                                          ______________________________________                                    

In Examples 12-1, 12-2 and 12-3, the stability of vitamin A is improvedas compared with the Comparative Example. This is the effect accordingto the present invention.

Quantitative determination method of vitamin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

    ______________________________________                                        Example 12-4: Cream (% by weight)                                             ______________________________________                                        A.       Cetanol        3                                                              Glycerylmonostearate                                                                         2                                                              POE(25) Cetyl ether                                                                          1                                                              Stearic acid   3                                                              Vaseline       3                                                              Olive oil      3                                                              Isopropyl myristate                                                                          1                                                              Squalane       5                                                              Vitamin A      0.1                                                            BHT            0.05                                                           Perfume        q.s.                                                  B.       Propylene glycol                                                                             3                                                              Potassium hydroxide                                                                          0.2                                                            Monosodium glutamate                                                                         5                                                              Purified water To total amount 100                                   ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 12-5: Beauty essence                                                                    (% by weight)                                               ______________________________________                                        Carboxyvinyl polymer                                                                            0.4                                                         Glycerol          5                                                           Propylene glycol  5                                                           Arginine aspartate                                                                              0.001                                                       Triethanolamine   3.4                                                         POE(60) hydrogenated castor oil                                                                 0.5                                                         Vitamin A         0.001                                                       Squalane          1                                                           α-tocopherol                                                                              1                                                           Methyl paraben    0.2                                                         Ethyl alcohol     6                                                           Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 12-6: Cosmetic lotion                                                                   (% by weight)                                               ______________________________________                                        Glycerol          2                                                           Ethanol           7                                                           POE(50) Oleyl ether                                                                             0.5                                                         Oleyl alcohol     0.002                                                       Vitamin A         0.0001                                                      Aspartic acid     0.001                                                       Lactic acid       0.02                                                        Sodium lactate    0.1                                                         Methyl paraben    0.1                                                         Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 12-7: Oil gel                                                                           (% by weight)                                               ______________________________________                                        Vitamin A         1                                                           Glycerol tri 2-ethylhexanoate                                                                   40                                                          Oliver oil        19                                                          BHT               0.1                                                         BHA               0.05                                                        POE(20) octyldodecyl ether                                                                      16                                                          Glycerol          15                                                          Sodium glutamate  0.01                                                        Purified water    To total amount 100                                         ______________________________________                                    

    ______________________________________                                        Example 12-8: Beauty liquid                                                                        (% by weight)                                            ______________________________________                                        Vitamin A            0.3                                                      Isopropyl myristate  3                                                        POE(60) hydrogenated castor oil                                                                    0.6                                                      Gum xanthane         0.8                                                      Glycerol             30                                                       Propylene glycol     5                                                        Sodium pyrrolidone carboxylate (50%)                                                               20                                                       Ethanol              6                                                        Methyl paraben       0.1                                                      Purified water       To total amount 100                                      ______________________________________                                    

    ______________________________________                                        Example 12-9: Night cream                                                                       (% by weight)                                               ______________________________________                                        Squalane          15                                                          Microcrystalline wax                                                                            4                                                           Isopropyl myristate                                                                             5                                                           Vaseline          4                                                           Octyl dodecanol   2                                                           Butyl paraben     0.15                                                        Vitamin A         0.2                                                         Diglycerol diisostearate                                                                        4                                                           Glycerol          3                                                           Propylene glycol  3                                                           Sodium glutamate  1                                                           Purified water    To total amount 100                                         ______________________________________                                    

The external skin treatment compositions of Examples 12-4 to 12-9 wereexcellent in the stability of vitamin A in daily use.

In the external skin treatment composition of the present invention, byformulating an acidic amino acid and/or the salt thereof, stability ofvitamin A can be extremely improved.

Examples 13-1 to 13-3 and Comparative Examples 13-1 to 13-2

                  TABLE 13-1                                                      ______________________________________                                        Vitamin A stability determination                                             results in oil (% by weight)                                                           Ex-   Ex-     Ex-     Comp.  Comp.                                            ample ample   ample   Example                                                                              Example                                          13-1  13-2    13-3    13-1   13-2                                    ______________________________________                                        Vitamin A  1       1       1     1      1                                     Pentaerythritol                                                                          99      49      --    --     --                                    ester                                                                         Trimethylol-                                                                             --      50      99    --     --                                    propane ester                                                                 Squalane   --      --      --    99     --                                    Cetylisooctanoate                                                                        --      --      --    --     99                                    Vitamin A quantitative determination value                                    Immediately after                                                                        99      100     99    100    100                                   preparation (%)                                                               After one month                                                                          96      94      92    40     51                                    at 40° C. (%)                                                          ______________________________________                                         Pentaerythritol ester: pentaerythritotetra(2-ethylhexanoate) ester            Trimethylolpropane ester: trimethylolpropanetri(2-ethyl-hexanoate)ester  

Quantitative determination method of vitamin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

In Examples 13-1, 13-2, and 13-3, the stability of vitamin A is improvedas compared with the Comparative Example. This is the effect accordingto the present invention.

Examples 13-4, 13-5 and Comparative Examples 13-3, 13-4

BHT and tocopherol are each completely dissolved in oil at 60° C., thenthe resulting solution is cooled to 40° C. Thereafter, vitamin A iscompletely dissolved therein. The resulting solution is filled in abrown glass sample tube and is stored in a constant temperature bath at40° C.

                  TABLE 13-2                                                      ______________________________________                                        Cosmetic oil formulation and vitamin A                                        stability determination results (% by weight)                                                            Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              13-4   13-5     13-3     13-4                                      ______________________________________                                        Trimethylolpropane                                                                         75       10       --     --                                      (2-ethylhexanoate)                                                            Pentaerythritol                                                                            --       80       --     --                                      (2-ethylhexanoate)                                                            Dimethylpolysiloxane                                                                       --       9.76     --     39.76                                   Isopropylmyristate                                                                         --       --       15     60                                      Squalane     24.985   --       84.985 --                                      Vitamin A    0.01     0.2      0.01   0.2                                     BHT          0.005    0.03     0.005  0.03                                    d1-α-tocopherol                                                                      --       0.01     --     0.01                                    Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After two months at                                                                        96       97       59     73                                      40° C. (%)                                                             ______________________________________                                    

In Examples 13-4 and 13-5, as compared with the Comparative Example, thestability of vitamin A is improved. This is the effect according to thepresent invention.

Production method and temperature test method of Examples 13-6, 13-7 andComparative Examples 13-5, 13-6

BHT, tocopherol and each oil and a surfactant are completely dissolvedat 70° C., thereafter, immediately before emulsification, vitamin A iscompletely dissolved therein to form an oil phase.

Glycerol, propylene glycol, carboxyvinyl polymer and caustic potash arecompletely dissolved in purified water. The oil phase is added to theresulting aqueous phase heated to 70° C., then the mixture obtained isemulsified by a homomixer type emulsifier. Then the resulting product issubjected to a cooling treatment by a heat exchanger to 30° C. to forman emulsion.

The emulsion is filled in a glass bottle having a metal coat appliedthereto, which is tightly sealed and is stored in a constant temperaturebath at 40° C.

                  TABLE 13-3                                                      ______________________________________                                        Emulsion formulation and vitamin A quantitative determination results         (% by weight)                                                                                            Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              13-6   13-7     13-5     13-6                                      ______________________________________                                        Pentaerythritol                                                                            10       4        --     --                                      (2-ethylhexanoate)                                                            Trimethylolpropane                                                                         --       3        --     --                                      (2-ethylhexanoate)                                                            BHT          0.05     0.01     0.05   0.01                                    d1-α-tocopherol                                                                      0.01     0.02     0.01   0.02                                    Vitamin A    0.3      0.01     0.3    0.01                                    Cetylisooctanoate                                                                          --       --       10     7                                       Squalane     5        2        5      2                                       Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     1        1        1      1                                       Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60)                                                                       Hydrogenated castor                                                                        1.3      1.3      1.3    1.3                                     oil                                                                           Carboxyvinyl polymer                                                                       0.2      0.2      0.2    0.2                                     Caustic Potash                                                                             0.06     0.06     0.06   0.06                                    Glycerol     10       10       10     10                                      Propylene glycol                                                                           3        3        3      3                                       Ethyl paraben                                                                              0.2      0.2      0.2    0.2                                     Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month at                                                                         98       96       32     25                                      40° C. (%)                                                             ______________________________________                                    

In Examples 13-6 and 13-7, the stability of vitamin A is improved ascompared with the Comparative Example. This is the effect according tothe present invention.

Quantitative determination method of vitamin A

According to the absorbance determination method at 325 nm usingethanol, the quantitative determination was effected.

In the calculation, at the maximum absorption 325 nm, E (1%, 1 cm)=1835was used

    ______________________________________                                        Example 13-8: Cosmetic lotion                                                                    (% by weight)                                              ______________________________________                                        Pentaerythritoltetracaprate                                                                      0.002                                                      tocopherol         0.001                                                      α-tocopherol 0.0005                                                     Vitamin A          0.0001                                                     POE(50) Oleylether 0.7                                                        Lactic acid        0.1                                                        Sodium lactate     0.9                                                        Ethanol            5                                                          Glycerol           1                                                          Methyl paraben     0.2                                                        Trisodium edetate  0.01                                                       Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 13-9: Oil essence                                                                         (% by weight)                                             ______________________________________                                        Pentaerythritoltetra (2-hexanoate)                                                                60                                                        Trimethyrolpropanetricaprate                                                                      10                                                        Squalane            10                                                        BHT                 1                                                         α-tocopherol  9                                                         Vitamin A           5                                                         ______________________________________                                    

    ______________________________________                                        Example 13-10: Cream (% by weight)                                            ______________________________________                                        Glycerol tri 2-ethylhexanoate                                                                      10                                                       Pentaerythritoltetra (2-ethylhexanoate)                                                            15                                                       BHT                  0.05                                                     BHA                  0.01                                                     α-tocopherol   0.01                                                     Vitamin A            0.3                                                      Vaseline             2                                                        Squalane             8                                                        Butyl paraben        0.1                                                      Propyl paraben       0.1                                                      Glycerol monooleate  3                                                        Diglycerol diisostearate                                                                           2                                                        PEG400 dioleate      1                                                        Glycerol             10                                                       Dipropylene glycol   5                                                        Purified water       To total amount 100                                      ______________________________________                                    

    ______________________________________                                        Example 13-11: Eye wrinkle oil                                                                     (% by weight)                                            ______________________________________                                        Pentaerythritoitetra(2-ethylhexanoate)                                                             40                                                       Trimethyrolpropanetricaprate                                                                       20                                                       Glycerol tri 2-ethylhexanoate                                                                      20                                                       Squalane             19                                                       Acetic acid palmitate                                                                              1                                                        ______________________________________                                    

The external skin treatment compositions of Examples 13-8 to 13-11 wereexcellent in the stability of vitamin A in daily use.

In the external skin treatment composition of the present invention, byformulating at least one polar oil component selected from the groupcosisting of pentaerythritol fatty acid ester and trimethylol propanefatty acid ester, the stability of vitamin A can be improved.

In accordance with the present invention, by formulating at least onepolar oil selected from the group consisting of pentaerythritol fattyacid ester and trimethylolpropane fatty acid ester, and at least oneoil-soluble antioxidant selected from the group consisting of butylhydroxytoluene, butyl hydroxyanisole, α,β,γ,δ-tocopherol,nordihydrogualaretin, propyl gallate, a fatty acid ester of vitamin Cand sorbic acid, the stability of vitamin A can be further noticeablyimproved.

Examples 14-1 to 14-2 and Comparative Examples 14-1 to 14-2

                  TABLE 14-1                                                      ______________________________________                                        Vitamin A stability determination results in emulsion (% by weight)                                      Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              14-1   14-2     14-1     14-2                                      ______________________________________                                        Purified water                                                                             To total amount 100                                              Glycerol     10       10       10     10                                      Ethyl alcohol                                                                              5        5        5      5                                       Methyl paraben                                                                             0.1      0.1      0.1    0.1                                     Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       2        2        2      2                                       castor oil                                                                    Cetyl alcohol                                                                              2        2        2      2                                       Isopropyl myristate                                                                        4        4        4      4                                       Vaseline     3        3        3      3                                       Squalane     5        5        5      5                                       BHT          --        0.05    --     0.05                                    Trisodium edetate                                                                          --       0.03     --     0.03                                    Natural      2        2        --     --                                      montmorillonite                                                               Vitamin A    0.3      0.3      0.3    0.3                                     Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month at                                                                         90       95       53     68                                      40° C. (%)                                                             ______________________________________                                         *Natural montmorillonite: Trade name Kunipia G4                          

Quantitative determination method of vitanin A

In accordance with the second method of vitamin A quantitativedetermination method, Japanese Pharmacopoeia (11th revision), thequantitative determination was effected by an absorbance determinationmethod using isopropanol.

In Examples 14-1, 14-2, the stability of vitamin A is improved ascompared with Comparative Example. This is the effect according to thepresent invention.

                  TABLE 14-2                                                      ______________________________________                                        Emulsion formulation and vitamin A quantitative determination results         (% by weight)                                                                                            Comp.    Comp.                                                Example                                                                              Example  Example  Example                                              14-3   14-4     14-3     14-4                                      ______________________________________                                        Natural saponite                                                                           3        3        --     --                                      (Veegum HV)                                                                   Ascorbic acid                                                                              0.1      --       0.1    --                                      BHT          0.05     0.01     0.05   0.01                                    d1-α-tocopherol                                                                      0.01     0.02     0.01   0.02                                    Vitamin A    0.3      0.01     0.3    0.01                                    Cetylisooctanoate                                                                          10       7        10     7                                       Squalane     5        2        5      2                                       Cetyl alcohol                                                                              2        2        2      2                                       Vaseline     1        1        1      1                                       Glyceryl monostearate                                                                      1.5      1.5      1.5    1.5                                     POE(60) hydrogenated                                                                       1.3      1.3      1.3    1.3                                     castor oil                                                                    Glycerol     10       10       10     10                                      Propylene glycol                                                                           3        3        3      3                                       Methyl paraben                                                                             0.2      0.2      0.2    0.2                                     Purified water                                                                             To total amount 100                                              Vitamin A quantitative determination value                                    Immediately after                                                                          100      100      100    100                                     preparation (%)                                                               After one month at                                                                         95       92       63     51                                      40° C. (%)                                                             ______________________________________                                    

    ______________________________________                                        Example 14-5: Cream                                                                              (% by weight)                                              ______________________________________                                        A.    Cetanol          3                                                            Glycerylmonostearate                                                                           2                                                            POE(25) cetyl ether                                                                            1                                                            Stearic acid     3                                                            Vaseline         3                                                            Olive oil        3                                                            Isopropyl palmitate                                                                            1                                                            Squalane         5                                                            Vitamin A        0.1                                                          BHT              0.05                                                         Perfume          q.s.                                                   B.    Propylene glycol 3                                                            Potassium hydroxide                                                                            0.2                                                          Synthetic saponite                                                                             0.1                                                          (Trade name: Smectone SA)                                                     Citric acid      0.001                                                        Purified water   To total amount 100                                    ______________________________________                                    

The oil phase portion (A) and the aqueous phase portion (B) arethermally melted at 70° C., then A is added to B, the resulting mixtureis emulsified, and subsequently subjected to a cooling treatment to forma cream.

    ______________________________________                                        Example 14-6: Beauty gel                                                                           (% by weight)                                            ______________________________________                                        Synthetic hectlite   10                                                       (Trade name: Laponite XLG)                                                    Glycerol             15                                                       Propylene glycol     5                                                        Citric acid          0.5                                                      Triethanolamine      1.8                                                      2-hydroxy-4-methoxybenzophenone-5-                                                                 1                                                        sodium sulfonate                                                              POE(60) hydrogenated castor oil                                                                    0.5                                                      Vitamin A            0.1                                                      Octylmetroxycinnamate                                                                              9                                                        Methyl paraben       0.2                                                      Ethyl alcohol        3                                                        Purified water       To total amount 100                                      ______________________________________                                    

    ______________________________________                                        Example 14-7: Cosmetic lotion                                                                    (% by weight)                                              ______________________________________                                        Glycerol           2                                                          Ethanol            7                                                          POE(50) Oleyl ether                                                                              0.5                                                        Oleyl alcohol      0.002                                                      Vitamin A          0.0001                                                     Synthetic saponite 0.01                                                       (Trade name: Smectone SA)                                                     Lactic acid        0.01                                                       Sodium lactate     0.09                                                       Methyl paraben     0.1                                                        Purified water     To total amount 100                                        ______________________________________                                    

    ______________________________________                                        Example 14-8: Cream (% by weight)                                             ______________________________________                                        Squalane            15                                                        Glycerol tri 2-ethylhexanoate                                                                     10                                                        Olive oil           10                                                        Butyl paraben       0.2                                                       Diglycerol diisostearate                                                                          2                                                         Glycerylmonooleate  2                                                         Natural saponite    3                                                         (Trade name: Veegum HV)                                                       Dimethylstearylammoniumchloride                                                                   1.0                                                       Vitamin A           0.5                                                       BHT                 0.1                                                       Disodium edetate    0.01                                                      Ascorbic acid       0.01                                                      Sodium isoascorbate 0.01                                                      2-hydroxy-4-methoxybenzophenone                                                                   0.3                                                       Glycerol            10                                                        Phenoxy ethanol     0.1                                                       Purified water      To total amount 100                                       ______________________________________                                    

    ______________________________________                                        Example 14-9: Oil gel                                                                             (% by weight)                                             ______________________________________                                        Vitamin A           1                                                         Glycerol tri 2-ethylhexanoate                                                                     40                                                        α-tocopherol  9                                                         Squalane            10                                                        Natural montmorillonite                                                                           10                                                        (Trade name: Kunipia G)                                                       Natural saponite    10                                                        (Trade name: Veegum HV)                                                       BHT                 1                                                         2-ethylhexyl paradimethylbenzoate                                                                 10                                                        POE(20) hydrogenated castor oil                                                                   6                                                         Purified water      4                                                         ______________________________________                                    

    ______________________________________                                        Example 14-10: Beauty powder                                                                     (% by weight)                                              ______________________________________                                        Synthetic hectlite 50                                                         (Trade name: Laponite XLG)                                                    D-mannitol         48                                                         Isopropyl palmitate                                                                              1.9                                                        Vitamin A          0.1                                                        ______________________________________                                    

    ______________________________________                                        Example 14-11: Beauty essense                                                                      (% by weight)                                            ______________________________________                                        Synthetic hectlite   3                                                        (Trade name: Laponite XLG)                                                    Synthetic saponite   1                                                        (Trade name: Smectone SA)                                                     Glycerol             20                                                       Propylene glycol     5                                                        Citric acid          0.03                                                     Trisodium citrate    0.07                                                     α-tocopherol   1                                                        2-hydroxy-4-methoxybenzophenone-5-                                                                 0.5                                                      Sodium sulfonate                                                              4-t-butyl-4'-methoxydibenzoylmethane                                                               0.1                                                      POE(60) hydrogenated castor oil                                                                    0.5                                                      Vitamin A            0.1                                                      Sodium hexametaphosphate                                                                           0.02                                                     Methyl paraben       0.2                                                      Ethyl alcohol        3                                                        Purified water       To total amount 100                                      ______________________________________                                    

The external skin treatment compositions of Examples 14-5 to 14-11 wereexcellent in the stability of vitamin A in daily use.

In the external skin treatment composition of the present invention, byformulating at least one water-swellable clay mineral, the stability ofvitamin A can be improved.

In accordance with the present invention, by formulating at least onewater-swellable clay mineral and at least one antioxidant, chelatingagent and ultraviolet absorber, the stability of vitamin A can befurther noticeably improved.

We claim:
 1. An external skin treatment composition comprising (I) vitamin A and (II) at least one stabilizer selected from the group consisting of:(1) (i) at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT), butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate, fatty acid esters of vitamin C and sorbic acid, (ii) at least one ethylenediaminetetraacetate and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (2) (i) at least one oil-soluble antioxidant selected from the group consisting of BHT, BHA, α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C, (ii) at least one compound selected from the group consisting of ascorbic acid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts, sorbic acid and sorbic acid salts and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (3) inclusion compounds of (i) cyclodextrins including (ii) at least one compound selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C, sorbic acid, benzophenones-1 to 10 and 12, cinnamic acid compounds, salicylic acid compounds, benzoic acid compounds, and dibenzoylmethane compounds; (4) (i) 1,3-butanediol and/or (ii) at least one oil-soluble antioxidant selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C and sorbic acid; and (5) at least one water-soluble benzophenone compound, wherein the composition comprises 0.0001% by weight or more of vitamin A, and(A) 0.001% by weight or more of (1) (i) the oil-soluble antioxidant, (B) 0.001% by weight or more of (1)(ii) the ethylenediaminetetraacetate, (C) 0.001% by weight or more of (1) (iii) the benzophenone compound, on the basis of the total weight of the composition.
 2. An external skin treatment composition comprising (I) vitamin A and (II) at least one stabilizer selected from the group consisting of:(1) (i) at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT). butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate, fatty acid esters of vitamin C and sorbic acid, (ii) at least one ethylenediaminetetraacetate and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3 benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (2) (i) at least one oil-soluble antioxidant selected from the group consisting of BHT, BHA α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C, (ii) at least one compound selected from the group consisting of ascorbic acid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts, sorbic acid and sorbic acid salts and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (3) inclusion compounds of (i) cyclodextrins including (ii) at least one compound selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C, sorbic acid, benzophenones-1 to 10 and 12, cinnamic acid compounds, salicylic acid compounds, benzoic acid compounds, and dibenzoylmethane compounds; (4) (i) 1,3-butanediol and/or (ii) at least one oil-soluble antioxidant selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C and sorbic acid; and (5) at least one water-soluble benzophenone compound, wherein the composition comprises 0.0001% by weight or more of vitamin A, and(A) 0.001% by weight or more of (2) (i) the oil-soluble antioxidant, (B) 0.001% by weight or more of (2) (ii) the compound, and (C) 0.001% by weight or more of (2) (iii) the benzophenone compound, on the basis of the total weight of the composition.
 3. An external skin treatment composition comprising (I) vitamin A and (II) at least one stabilizer selected from the group consisting of:(1) (i) at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT) butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate, fatty acid esters of vitamin C and sorbic acid, (ii) at least one ethylenediaminetetraacetate and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (2) (i) at least one oil-soluble antioxidant selected from the group consisting of BHT, BHA, α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C, (ii) at least one compound selected from the group consisting of ascorbic acid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts, sorbic acid and sorbic acid salts and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (3) inclusion compounds of (i) cyclodextrins including (ii) at least one compound selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γδ-tocopherols, propyl gallate, a fatty acid ester of vitamin C, sorbic acid, benzophenones-1 to 10 and 12, cinnamic acid compounds, salicylic acid compounds, benzoic acid compounds, and dibenzoylmethane compounds; (4) (i) 1,3-butanediol and/or (ii) at least one oil-soluble antioxidant selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C and sorbic acid; and (5) at least one water-soluble benzophenone compound, wherein the composition comprises 0.0001% by weight or more of vitamin A, 0.01% by weight or more of (3) (i) the cyclodextrin including 0.001% by weight or more of (3) (ii) the compound, on the basis of the total weight of the composition.
 4. An external skin treatment composition comprising (I) vitamin A and (II) at least one stabilizer selected from the group consisting of:(1) (i) at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT), butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate, fatty acid esters of vitamin C and sorbic acid, (ii) at least one ethylenediaminetetraacetate and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (2) (i) at least one oil-soluble antioxidant selected from the group consisting of BHT, BHA, α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C, (ii) at least one compound selected from the group consisting of ascorbic acid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts, sorbic acid and sorbic acid salts and, (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (3) inclusion compounds of (i) cyclodextrins including (ii) at least one compound selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C, sorbic acid, benzophenones-1 to 10 and 12, cinnamic acid compounds, salicylic acid compounds, benzoic acid compounds, and dibenzoylmethane compounds: (4) (i) 1,3-butanediol and/or (ii) at least one oil-soluble antioxidant selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C and sorbic acid; and (5) at least one water-soluble benzophenone compound, wherein the composition comprises 0.0001% by weight or more of vitamin A, 0.01% by weight or more of (4) (i) the 1,3-butanediol and 0.001% by weight or more of (4) (ii) the oil-soluble antioxidant, on the basis of the total weight of the composition.
 5. An external skin treatment composition comprising (I) vitamin A and (II) at least one stabilizer selected from the group consisting of:(1) (i) at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT), butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate, fatty acid esters of vitamin C and sorbic acid, (ii) at least one ethylenediaminetetraacetate and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (2) (i) at least one oil-soluble antioxidant selected from the group consisting of BHT, BHA, α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C, (ii) at least one compound selected from the group consisting of ascorbic acid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts, sorbic acid and sorbic acid salts and (iii) at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12; (3) inclusion compounds of (i) cyclodextrins including (ii) at least one compound selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C, sorbic acid, benzophenones-1 to 10 and 12, cinnamic acid compounds, salicylic acid compounds, benzoic acid compounds, and dibenzoylmethane compounds; (4) (i) 1,3-butanediol and/or (ii) at least one oil-soluble antioxidant selected from the group consisting of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C and sorbic acid; and (5) at least one water-soluble benzophenone compound, wherein the composition comprises 0.0001% by weight or more of vitamin A and 0.001% by weight or more of (5) the water-soluble benzophenone compound, on the basis of the total weight of the composition.
 6. An external skin treatment composition comprising, all on a basis of a total weight of the composition, (I) 0.0001 % by weight or more of vitamin A and (II) at least one stabilizer comprising 0.001 % by weight or more of at least one benzophenone compound selected from the group consisting of benzophenone-1, benzophenone-2, benzophenone-3, benzophenone4, benzophenone-5, benzophenone-6, benzophenone-7, benzophenone-8, benzophenone-9, benzophenone-10 and benzophenone-12.
 7. The composition of claim 6, further comprising at least one of (i) or (ii):(i) 0.001 % by weight or more of at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT), butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C; and (ii) 0.001 % by weight or more of at least one ethylenediaminetetraacetate.
 8. The composition of claim 6, further comprising at least one of (i) or (ii):(i) 0.001% by weight or more of at least one oil-soluble antioxidant selected from the group consisting of butyl hydroxytoluene (BHT), butyl hydroxyanisole (BHA), α,β,γ,δ-tocopherol, nordihydrogualaretin, propyl gallate and fatty acid esters of vitamin C; and (ii) 0.001% by weight or more of at least one compound selected from the group consisting of ascorbic acid, ascorbic acid salts, isoascorbic acid, isoascorbic acid salts, sorbic acid and sorbic acid salts.
 9. An external skin treatment composition comprising, all on a basis of a total weight of the composition, (I) 0.0001 % by weight or more of vitamin A and (II) at least one stabilizer comprising 0.01% by weight or more of inclusion compounds of (i) cyclodextrins including (ii) 0.001% by weight or more of at least one compound selected from the group consisting of benzophenones-1 to 10 and 12, cinnamic acid compounds, salicylic acid compounds, benzoic acid compounds, and dibenzoylmethane compounds.
 10. The composition of claim 9, further comprising at least one of nordihydrogualaretin, BHT, BHA, α,β,γ,δ-tocopherols, propyl gallate, a fatty acid ester of vitamin C and sorbic acid.
 11. An external skin treatment composition comprising, all on a basis of a total weight of the composition, (I) 0.0001 % by weight or more of vitamin A and (II) at least one stabilizer comprising 0.001 % by weight or more of at least one water soluble benzophenone compound. 